Patient care and communication system

ABSTRACT

The present invention relates to a patient care and communication system which utilizes a central processing system and a plurality of remote stations electrically connected to the central processing system to facilitate visual and data communications. Each remote station includes telephone circuitry which is connected to a private branch exchange for telephone communications between stations. In addition, the private branch exchange is connected to a telephone exchange and a plurality of telephones for facilitating telephone communication therebetween. The central processing system facilitates the visual and data communications between the plurality of remote stations, and includes a system for determining which of the plurality of remote stations are transmitting the visual and data communications and which of the plurality of remote stations are to receive the visual and data communications. The central processing system also includes a system which establishes a communication link between the transmitting stations and the receiving stations. The remote stations include a processing system which also facilitates the visual, data and telephone communications and a display for displaying the visual communications. The present invention also includes a staff and/or patient locator system, in which each remote station includes an infrared receiver that receives infrared transmissions from a portable transmitter worn by a staff member or patient. The infrared transmissions include identity information associated with the person wearing the transmitter. The identity information is then transferred to the central processing system which determines the identity and location of each person wearing a portable transmitter.

CROSS REFERENCE TO RELATED APPLICATION

This is a continuation of application Ser. No. 08/923,227, filed Sep. 4,1997 now U.S. Pat. No. 6,259,355, which is a continuation-in-part ofapplication Ser. No. 08/087,394, filed Jul. 2, 1993 now U.S. Pat. No.5,455,851, and is a continuation-in-part of application Ser. No.08/033,287, filed Mar. 16, 1993 abandoned, which is acontinuation-in-part of application Ser. No. 07/924,101, filed Aug. 3,1992 now U.S. Pat. No. 5,465,082, which is a continuation-in-part ofapplication Ser. No. 07/559,196 filed on Jul. 27, 1990 now U.S. Pat. No.5,291,399.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a patient care and communication systemwhich incorporates telephone communication therein. The system utilizesa PBX to provide staff-to-staff, staff-to-patient and/or externaltelephone communications. The system is also capable of performing taskssuch as monitoring medical equipment in patient rooms and maintainingpatient medical data; facilitating staff-to-staff or staff-to-patientvisual and data communications; and tracking the location of staffmembers or patients to provide maximum patient care. More detaileddescriptions of the staff-patient communications and the monitoring ofthe medical equipment is provided in application Ser. No. 08/033,287,filed Mar. 16, 1993 which is incorporated herein by reference. A moredetailed description of the, system for tracking the location ofpersonnel is provided in application Ser. No. 08/087,394, filed Jul. 2,1993 and application Ser. No. 07/924,101, filed Aug. 3, 1992 both ofwhich are incorporated herein by reference.

2. Description of the Related Art

In hospital or other health care environments, the nursing staff as wellas other staff members are required to maintain and update patientinformation, provide patient care, and assist physicians in thetreatment of patients. Often, these tasks have to be performed eventhough there are personnel shortages. Further, as medical technologycontinues to develop to provide treatment for a greater number ofmedical conditions, the volume of information that is maintained foreach patient continues to grow rapidly. As a result, stress on thenursing staff has increased and information overload is fastapproaching.

To more fully understand the above problem relating to health care,consider the types of data which are maintained for an individualpatient. Typically, the staff members need to know the patient's nameand address as well as any special dietary, environmental or physicalspace requirements of the patient. The attending physician or nursingstaff may want to know the patient's condition,, medical history andrecent vital sign data. If the patient has had any diagnostic tests suchas x-rays or ultrasound images made at the hospital, or at any otherhospital, the attending physician may want to compare these test resultswith the results of newer tests to see how the patient's condition hasprogressed. In addition, if any medication has been prescribed, thephysician or nursing staff may want to know the identity of themedication, when the last dose was taken and how the patient hascomplied with the dosage schedule.

Current systems utilized to manage such information includes the manualwriting and processing of the information. Electronic systems utilizedto process and store the information involve multiple computers, eachconfigured to process portions of the vast amount of information. Toobtain all the information in one place the information stored in eachcomputer system must be manually combined. Furthermore, such electronicsystems do not provide visual displays of text at stations provided inthe patient's room, at the nurse control station or at stations providedin areas of the health care facility frequently occupied by the healthcare personnel.

In addition to processing the above information, the nursing staffattending to a number of patient's rooms may want to have someindication of each patient's condition at nursing stations which are farremoved from the patient's bed. For example, if the patient has beenadmitted for a heart condition, it would be helpful if any recent vitalsigns that may indicate the onset of a heart attack could be displayedat the nurses station when the patient presses a call button.

One such system described in U.S. Pat. No. 4,835,372 to Gombrich et al.relates to a patient identification system for relating items withpatients and for ensuring that an identified item corresponds to anidentified patient. The system includes a computer system interconnectedto a plurality of remote terminals by conventional telephone wiring. ARF modem provides for transmission and reception of RF signals to andfrom a bar code reading device, and the RF modem provides fortransmission and reception of signals via existing telephone wire to andfrom the computer system using data over voice technology.

Another problem faced by care givers and by hospital administrators isdetermining the location of key personnel and equipment. In an emergencyor during periods of personnel shortages, the ability to quickly locatean attending physician or other staff member to provide maximum patientcare is desirable. Moreover, when special equipment is required to treatan emergency condition or when a ward of a hospital is experiencingpersonnel shortages, it is desirable that the equipment be quicklylocated to reduce the time spent to locate the equipment.

One type of system utilized to locate personnel within a hospital orother health care facility relies on audio paging systems, sign-in andsign-out sheets and broadcast paging systems. In a given situation, theaudio paging system would be tried first. This system may not beeffective if the person to be located is in an area where the pagingsystem is not functioning properly or has been turned down, or if theperson has left the hospital. After an unsuccessful audio page, thesign-in and sign-out sheets may be checked. If, however, the person tobe located forgot to use the sign-in sheet or sign-out sheet, criticaltime may be lost in a second attempt to use the audio paging system. Inaddition, a search of the sign-in and sign-out sheets may require moretime than is available in an emergency situation.

When the person to be located is outside of the hospital, broadcastpaging systems are often the best way to convey an important message.These systems require the individual trying to locate the person to callthe paging service, leave a message, wait for the paging service to sendthe message to the individual's pocket pager and then wait for theperson being paged to call the paging service, receive the message andrespond.

Another type of currently used locator system utilizes either radiofrequency signals or infra-red signals to communicate the position of amobile individual or object to a network of stationary transceivers. Onesuch system, the InfraCom locating and signaling system available fromUnited Identification Systems Corp. is designed for use in a hospitalenvironment. Using this system, a network of infra-red transceiverslocated throughout a hospital can both transmit data to and receive datafrom a portable badge worn by hospital personnel or attached to theequipment to be located. This badge transmits a programmedidentification signal to the network allowing the position of the badgeto be indicated on a display of the floor plan of the hospital.

Another exemplary system, the TELOC PLUS personnel locator systemavailable from Teloc, Inc., also uses two-way infra-red signaling tocommunicate the position of a portable badge in a stationarytransceiver. In addition, the Teloc system may be coupled to a privatebranch exchange (PBX) to allow telephone calls from an individual to berouted to the telephone that is closest to the badge or to direct anintercom message to that telephone, thus providing an alternative to anaudio paging system. Each of these systems is limited in the type ofinformation that may be conveyed between the stationary transceivernetwork and the transceiver on the badge. In the described systems, onlyidentification information providing an indication that switches, whichare located on the badge have been activated, may be transmitted fromthe badge. Furthermore, if the transceiver on the badge fails or isdamaged, a blank badge must be programmed to take its place. Thisprogram operation may be time consuming, leaving the individual or thepiece of equipment invisible to the locating system for that period oftime.

Therefore, a need exists for a patient care and communication systemwhich integrates a staff locating system with a system which facilitatesvisual and data communications between staff members and patients andwhich maintains patient data. A need also exists for a patient care andcommunication system which utilizes a private-branch exchange to providestaff-to-staff, staff-to-patient and/or external communications. Thepresent invention provides a patient care and communication system whichprovides communications through a PBX and which is capable of performingtasks such as monitoring medical equipment in patient rooms andmaintaining patient medical data, facilitating voice, visual and datacommunications between staff members and the patients, as well as asystem for tracking staff members to provide maximum patient care.

SUMMARY OF THE INVENTION

The present invention relates to a patient care and communication systemwhich includes a central station having means for facilitating visualand data communications relating to health care and a plurality ofremote stations connected to the central station. The remote stationsinclude processing means for facilitating the visual and datacommunications and display means for displaying the visualcommunications.

The central station includes means for determining which of theplurality of remote stations are transmitting the visual and datacommunications and which of the plurality of remote stations are toreceive the visual and data communications. In addition, the centralstation includes means for establishing a communication link between thetransmitting stations and the receiving stations, and each of theplurality of remote stations includes telephone circuitry for connectionto a private-branch exchange for telephone communications therebetween.

Preferably, the plurality of remote stations includes control stations,patient stations and staff stations and the central station includesmeans for directing the visual and data signals transmitted to thecontrol stations to a predetermined number of patient stations and apredetermined number of staff stations.

The present invention also provides a patient care and communicationsystem where the plurality of remote stations are configured and adaptedfor association in a group network such that predefined visual and datasignal communications are transmitted to each station in the group. Zonecontroller means are provided to interface the central processing meansto the transmitting and receiving stations.

In the preferred embodiment, the central station also includes means forcontrolling the private-branch exchange to establish audio communicationbetween a predetermined number of control stations, a predeterminednumber of the patient stations and a predetermined number of the staffstations.

The patient stations of the present invention include patient controlmeans which is connected thereto and provide a remote communication linkbetween the patient and staff members or the patient and outsidecallers. The patient control means has a keypad, a speaker and amicrophone for telephone communications to other stations or forexternal telephone communications. It should be noted that externalcommunications includes telephone communications from within thehospital environment to locations outside the hospital environment,generally via public telephone lines.

The system of the present invention also relates to a method ofproviding patient care and communication between patient rooms and nursestations in a health care facility. The method includes the steps ofconnecting a plurality of remote stations to a central station so as tofacilitate visual and data communications therebetween, and connectingeach remote station and the central station to a private-branch exchangefor audio communications between the remote stations. At least one ofsaid plurality of remote stations is positioned in each patient roomlocated within the health care facility, positioning at least one ofsaid plurality of remote stations in each nurse station of said healthcare facility, attending the remote station in each nurse station toreceive the visual and data signals from said central station and theaudio signals from the PBX and responding to the audio, visual and datasignals.

BRIEF DESCRIPTION OF THE DRAWINGS

The preferred embodiments of the invention are described hereinbelowwith reference to the drawings wherein:

FIG. 1 is an illustration of the components of one embodiment of thepatient care and communication system configuration of the presentinvention;

FIG. 2 is a functional block diagram of an alternative embodiment of asystem configuration of the present invention;

FIG. 3 is a functional block diagram of an another alternativeembodiment of a system configuration of the present invention,illustrating grouping arrangements for the stations;

FIG. 4 is a functional block diagram of an another alternativeembodiment of a system configuration of the present invention;

FIG. 5 is a circuit block diagram for the central processing unitillustrated in FIG. 1;

FIG. 6 is flow-chart diagram for the central processing unit illustratedin FIG. 1;

FIG. 7 is a block diagram for the fail safe feature associated with thesystem of the present invention;

FIG. 8 is a flow-chart diagram of the fail safe feature illustrated inFIG. 7;

FIG. 9 is a functional block diagram of a system configuration similarto FIG. 1, illustrating a patient station having peripheral equipmentconnected thereto;

FIG. 10 is a block diagram for the nurse control station illustrated inFIG. 1;

FIG. 11 is a circuit block diagram for the audio circuitry of thekeyboard of the nurse control station illustrated in FIG. 1.

FIGS. 12 and 13 are circuit block diagrams for the internal circuitryfor the patient stations illustrated in FIG. 1;

FIGS. 14 a and 14 b illustrate an exemplary flow-chart diagram of anoperation of the patient station of FIG. 1;

FIG. 15 is a flow-chart diagram associated with the internal circuitryfor the patient stations illustrated in FIG. 1;

FIGS. 16 and 17 are circuit block diagrams for the internal circuitryfor the staff stations illustrated in FIG. 1;

FIGS. 18, 19 and 20 are tables which illustrate various call indicationsand associated tones generated by the stations in response to aparticular call condition;

FIG. 21 is flow-chart diagram for the central processing unitillustrated in, FIG. 12; and

FIG. 22 is a circuit diagram for the patient control unit illustrated inFIG. 10 and showing self-test circuitry for performing automaticcontinuity tests of interconnecting wires;

FIG. 23 is an illustration of the components of an alternativeembodiment of the patient care and communication system of the presentinvention;

FIG. 24 is a functional block diagram of the alternative embodiment ofthe patient care and communication system configuration of FIG. 23,illustrating a private-branch exchange connected to the stations fortelephone communications;

FIG. 25 is a circuit block diagrams for an alternative embodiment of theinternal circuitry for the patient stations illustrated in FIG. 23;

FIG. 26 illustrates the data frames for communication between thestations and the private-branch exchange;

FIG. 27 illustrates the data frames for communication from the stationsto the private-branch exchange in an expanded form;

FIG. 28 illustrates the data frames for communication from theprivate-branch exchange to the stations in an expanded form;

FIG. 29 is a circuit block diagram for an alternative embodiment of theinternal circuitry for the patient control units illustrated in FIG. 23;

FIG. 30 is a circuit block diagram for an alternative embodiment of theinternal circuitry for the nurse control stations illustrated in FIG.23;

FIG. 31 is an illustration of the components of another alternativeembodiment of the patient care and communication system configuration ofthe present invention;

FIG. 32 illustrates exemplary input and output waveforms for thewaveshaping and conditioning circuitry of FIG. 25;

FIG. 33 is a block diagram of the components of an exemplary portabletransmitter according to the present invention;

FIGS. 34-36 illustrate a side elevational view, top plan view and abottom plan view, respectively, of a housing for the transmittercomponents of FIG. 33;

FIGS. 37 and 38 illustrate front and rear views, respectively, of apersonnel card used with the transmitter housing and components of FIG.35;

FIG. 39 is an exemplary configuration for a patient room within a healthcare facility;

FIG. 40 is a circuit block diagram of an infrared receiver andenvironmental facilities within the patient room of FIG. 39, which areconnected to a controller;

FIG. 41 is an alternative configuration for a patient room within ahealth care facility, illustrating the utilization of a wireless systemfor controlling environmental facilities in the room; and

FIG. 42 is a block diagram of an alternative portable transmitterembodiment according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Generally, the patient care and communication system of the presentinvention includes a communication network that provides routine andemergency signaling to health care facility staff members and provideshigh fidelity voice communication and data transmission between staffmembers in the health care facility and/or between patients and thestaff members.

The exemplary embodiments of the automatic staff locator system of thepatient care and communication system of the present invention describedbelow, use a memory card as a personal database. As used herein, amemory card is a device approximately the same size and shape as anordinary credit card which includes a non-volatile programmable memory.In the card used in the embodiments described below, two types of memoryare used: an electronically erasable read only memory (EEROM) locatedinternal to the card and a magnetic stripe located on the surface of thecard. It is contemplated, however, that other forms of internal memory,such as a ferro-electric RAM or a CMOS memory with an integral battery,may be used. It is also contemplated that the functions described belowmay be implemented with other types of external memory, such as lasercard technologies which either augment or replace the card memory. Amore detailed description of the staff locator system and its operationis described in commonly assigned U.S. application Ser. No. 08/033,287,filed on Mar. 16, 1993 and which is incorporated herein by reference.

System Configurations and Communications

FIG. 1 is an illustration of the major components of the patient careand communication system according to the present invention, whichincludes central processor unit (CPU) 2412, nurse control stations 2414,patient stations 2416, staff stations 2418 and zone controllers 2420.Generally, the nurse control stations 2414 are installed at nursestations located in various areas of the hospital or health carefacility and provide a communication link to patients in their rooms.The patient stations 2416 are installed in patient rooms and can beconfigured to correspond to one patient or to multiple patients. Thepatient stations 2416 include patient station display 3230, speaker3618, microphone 3620 and patient control unit 3210, all of which willbe described in more detail below.

The staff stations 2418 are preferably installed in locations frequentlyoccupied by other staff members in the hospital, such as staff lockerrooms. Staff stations 2418 include staff station display 2422, speaker4018 and microphone 4020, all of which will also be described in moredetail below. The zone controllers 2420 include shared-RAM (S-RAM)memory 2512 (shown in FIG. 2) which is utilized as a buffer memory fordata received from either CPU 2412 or from any of the above notedstations, hence the term shared-RAM.

As will be described in more detail below, the various types of stationswhich are positioned at different locations within the hospital interactwith the aid of the CPU 2412 to perform numerous operations to reducethe information overload currently plaguing hospital staff members.Examples of the operations involving CPU 2412 include a call priorityoperation which prioritizes incoming calls (or messages) to nursecontrol station 2414 based upon the type of message received, so thatstaff members respond to the highest priority calls first. For example,if the incoming message relates to a fault in a smoke alarm secured inthe patient's room, that message will be given the highest priority.Another operational example is a nurse follow operation which allowsstaff members to selectively route incoming calls directed to a nursecontrol station, to selected patient stations and/or staff stations sothat when the staff members attending the nurse control station arerequired to leave the area, incoming calls to that station can be routedto locations where appropriate staff members can respond to the call.Another operational example is a voice paging operation which allowsstaff members to communicate with selected patient stations 2416 and/orstaff stations 2418 from the nurse control station 2414. The interactionbetween the stations when performing these exemplary operations ortasks, as well as other operations, is conducted via a communicationlink which will be described in more detail below.

FIG. 3 illustrates the major components of system 2410 arranged ingroups. As shown, CPU 2412 of the system of the present invention isconfigured, dimensioned and adapted to interface through zone controllersystems 2413 with a predetermined number of station groups of patientstations 2416, staff stations 2418, and/or any combination thereof(e.g., the number of groups ranging between 1 and x, where “x” ispreferably 8). Each station group includes between 1 and “n” stations,where “n” is preferably 35, and a predetermined number of station groupscan be assigned to between 1 and “m” nurse control stations 2414, where“m” is preferably 8. For example, if a ward in a hospital has onehundred patient rooms (numbered from 100 to 200) which are singleoccupancy rooms, a staff locker room (Room 201) and a staff kitchen(Room 202), one patient station 2416 would be installed in each patientroom and one staff station 2418 would be installed in the staff lockerroom and the staff kitchen. An exemplary array of station groupings (orthe call assignment configuration) is shown in Table I below:

TABLE I RM1 RM2 RM3 . . . RM32 RM33 RM34 RM35 GROUP 1 100 101 102 . . .132 133 201 202 GROUP 2 120 121 122 . . . 152 153 201 202 . . . GROUP 8154 155 156 . . . 186 187 201 202As shown in this exemplary call assignment configuration, rooms 100through 133, 201 and 202 are assigned to station group 1. Rooms 120through 153, 201 and 202 are assigned to station group 2 and rooms 154through 187, 201 and 202 are assigned to station group 8. The stationgroupings can overlap in room coverage, thus, as illustrated in table Iabove, station groups 1 and 2 both include rooms 120 through 133.

In addition to the station groupings, the system of the presentinvention is configured so that each station group is assigned to apredetermined number of nurse control stations 2414. Table II below,illustrates an exemplary call assignment configuration for stationgroupings and their assignment to the nurse control stations 2414:

TABLE II Group 1 Group 2 . . . Group 8 NCS1 YES YES . . . YES NCS2 YESNO . . . NO . . . NCS8 NO YES . . . NOIn this exemplary configuration, communication transmitted by any of thestations assigned to station group one (rooms 100-133, 201 and 202) willbe directed to nurse control station one (NCS1) and to NCS2 so thatstaff members attending either nurse control station 2414 can respond tothe call. Communications transmitted by any of the stations assigned tostation group two (rooms 120-153, 201 and 202) will be directed to NCS1and NCS8 so that staff members attending either nurse control station2414 can respond to the call. Communications transmitted by any of thestations assigned to station group eight (rooms 154-187, 201 and 202)will be directed to NCS1 so that staff members attending NCS1 canrespond to the call.

In the preferred embodiment, the patient care and communication systemof the present invention can include four call assignmentconfigurations. To illustrate, the call assignment configurations can beutilized to automatically (or manually) assign stations (2416 or 2418)to station groups and station groups to nurse control stations 2414 forday operation, for evening operation, for weekend operation and/or forholiday operation.

Referring now to FIG. 4 which illustrates an alternative systemconfiguration in which, central processing unit 2412 is connected toexternal communication equipment such as broadcast paging system 2720,external computer 2722, printer 2724, and/or staff locator system 2428.Broadcast paging system 2720 may be utilized by the system of thepresent invention to locate staff members or other personnel who are notwithin the hospital or other health care facility. The broadcast pagingsystem may be any known type capable of interfacing with a computer.Preferably, broadcast paging system 2720 and CPU 2412 communicate viaserial communication ports connected to each device. Staff locatorsystem 2428 may be provided to locate staff members anywhere in thehospital or other health care facility as described in U.S. applicationSer. No. 07/924,101, filed Aug. 3, 1992, which is incorporated herein byreference. In addition to locating staff members, staff locator system2428 may be utilized to track or locate patients in the hospital. Toutilize the staff locator system to locate patients, each patient isprovided with an identification badge or bracelet which includes thecomponents as disclosed for identification badge worn by staff membersand described above. The identification badge or bracelet continuallytransmits the identification signal of the patient and the centralcomputer system continually monitors the identification signal to updatethe location of the bracelet and the patient. The location informationof the staff member or patient is transferred to CPU 2412 via data link2726 (shown in FIG. 4) which may be any known type of communication linkutilized to facilitate communication between computer systems. Externalcomputer 2722 interfaces to CPU 2412 and performs computing functionsincluding extracting or inputting data stored or otherwise processedwithin CPU 2412. Printer 2724 may be utilized to extract hard copies ofdata stored or otherwise processed within CPU 2412 including problemreports generated by the system, as will be described in more detailbelow.

FIG. 2 illustrates a functional block diagram of an alternative systemconfiguration, which includes main hospital computer 2530 configured tointerface with CPU 2412 to provide staff members with additional patientinformation, or to transfer from CPU 2412 to the main hospital computerpatient information which may be utilized for billing purposes. Forexample, information pertaining to the types and quantities ofprescription or intravenous drugs taken by the patient and the types oftreatments received by the patient (e.g., X-rays or CT-scans), as wellas the physician time spent with the patient, may be transferred to themain hospital computer to provide the hospital with more accuratebilling information. Preferably, main hospital computer 2530 isinterfaced with CPU 2412 via hospital personal computer 2540, systempersonal computer 2550, RS-232/RS-484 converter 2520 and zone controller2560. In this configuration, the integrity of the main hospital computeris maintained and the serial conversion from RS-232 protocol to RS-484protocol is accomplished.

FIG. 5 illustrates the hardware components of central processing unit(CPU) 2412. The CPU 2412 includes microprocessor 2810, three Mbytes ofmemory 2820 (2 Mbytes of flash ROM and 1 Mbyte of RAM) having storedprograms (e.g., operating system and application programs), andcommunication interface 2830. Preferably, microprocessor 2810 is anMC68000 16-bit microprocessor manufactured by Motorola Inc. In additionto the above circuits, CPU 2412 includes watchdog circuit 2840 whichreceives a one shot trigger from microprocessor 2810, at a predeterminedtime interval, preferably 300 msec., to ensure that the microprocessoris functioning. If, however, microprocessor 2810 fails to timely triggerwatchdog circuit 2840, then the watchdog circuit will initiate anautomatic reset of the microprocessor, thus preventing themicroprocessor from locking-up for extended periods of time.

Communication interface 2830 and communication ports 2850 are providedto facilitate communication between CPU 2412 and zone controllers 2420and between CPU 2412 and the external communication equipment. As notedabove, the preferred communication protocol includes the RS-485 serialcommunication protocol. Accordingly, communication interface 2830 isconfigured to accommodate RS-485 communication utilizing RS-485drivers/receivers which are known in the art.

An exemplary operational flow of CPU 2412 is shown in FIG. 6. Initially,the CPU is in a listen mode. In the listen mode the CPU continuouslypolls or otherwise interrogates the different components attachedthereto. For example, as shown in FIG. 6, the CPU will periodically polleach shared-RAM (S-RAM) 2512 (shown in FIG. 2) of each zone controller(step 2910) in a manner described hereinbelow. If the S-RAM does nothave a message frame received from a station within the zone controllergrouping, CPU 2412 returns and polls the next zone controller (step2920). Preferably, as will be described in more detail below datatransmitted between the CPU 2412 and the zone controller 2420 or betweenthe zone controller 2420 and the stations (either 2414, 2416 or 2418)are in the form of message frames which include station identityinformation as well as the message data relating to a particularfunction.

If, however, the S-RAM does have a message frame stored therein, CPU2412 will retrieve the message frame (step 2930) and analyze thereceived message frame by determining what patient station, staffstation or nurse control station the message frame was received from andif the frame was received from a patient station, by organizing orobtaining any patient information associated with that particularpatient station (step 2940). The DATA field within the INFORMATION fieldof the received message frame is then interpreted by the CPU, whichdetermines whether a response to the associated patient station, staffstation or nurse control station message frame is necessary (step 2950).If a response is not required, CPU 2412 returns to poll the next zonecontroller.

However, if a response is due, the CPU then starts the task associatedwith the information included in the message frame (step 2960). Uponcompletion of the task, CPU 2412 returns to the listen mode and beginspolling the next zone controller connected thereto as described above.

The components of zone controller 2420 include a microcontroller, memoryhaving stored programs (e.g., system or application programs) and acommunication interface connected to communication ports. The connectionof the zone controller 2420 components is the same as equivalentcomponents of CPU 2412, as shown in FIG. 5. The zone controller 2420also includes the shared-RAM (S-RAM) 2512, shown in FIG. 2, which isconnected to the microcontroller. Preferably, the microcontroller is the64180 microcontroller, manufactured by Motorola and the S-RAM includes 2kilobytes of memory.

A communication interface and communication ports are provided tofacilitate communication between zone controller 2420, CPU 2412 andslave devices, such as patient station 2416, staff station 2418 and/ornurse control station 2414. The communication protocol may be any knownserial communication protocol, such as RS-232 or RS-485. The RS-485protocol is preferred in the embodiment according to the presentinvention. Accordingly, the communication interface is configured toaccommodate RS-485 communication utilizing RS-485 drivers/receiverswhich are known in the art. Each zone controller 2420 also includes awatchdog circuit which operates similarly to the watchdog circuit in CPU2412. Thus, the watchdog circuit prevents the microcontroller fromlocking-up if the watchdog circuit is not polled at the predeterminedtime interval, preferably 300 msec., by the microcontroller.

The communication link between the zone controllers and stations orbetween the stations and peripheral equipment connected to the stationis in a master-slave relationship. In the communication link between thezone controllers 2420 and the stations, the zone controllers are themaster stations and the nurse control stations, patient stations orstaff stations are the slave stations. Whereas, in the communicationlink between the stations and the peripheral equipment, the stations(e.g., the patient stations) are the master stations and the peripheralequipment is the slave. The master station is in control of the datalink and transmits command frames to the slave stations. The masterstation maintains separate sessions (i.e., communication links) witheach slave station attached to the link. To illustrate and againreferring to FIG. 2, if zone controller 2420 is connected to a group ofpatient stations (1 to n) and/or connected to a group of staff stations(l to m), the zone controller (master) will periodically poll eachpatient station (slave) to retrieve message frames. The slave stationresponds to the commands from the master station and can send onemessage to the master station per poll from the master station.

The master station may communicate with the slave stations in one of twological states. One state is the INITIALIZATION state which is used toinitialize the master/slave station (e.g., identify for eachcommunication link which device connected thereto is the master andwhich is the slave). A second state is the INFORMATION TRANSFER statewhich permits the master and slave stations to transmit and receivecontrol or application information transmitted across the data linkbetween the master station and the slave stations in the form of messageframes or blocks of data.

In the preferred embodiment, the message frames may be one of threetypes. The first type of message frame is the INFORMATION FORMAT frame(I-frame) which is used to transmit application information (e.g.,message information associated with a particular function or stationstatus data) between the master and slave stations. The I-frame may alsoacknowledge receipt of a frame from a transmitting station. The secondtype of message frame is the SUPERVISORY FORMAT frame (S-frame) whichperforms control functions, such as acknowledging the receipt of a pollfrom the master station or requesting the temporary suspension of thetransmission of I-frames. The third type of message frame is theUNNUMBERED FORMAT frame (U-frame) which is also used for controlpurposes, such as performing data link initialization or tests.

As noted, the data (or information) transmitted between master and slavestations is preferably configured in the form of a message frame. Thepreferred message frame includes five fields, similar to the frame shownbelow:

-   -   ADDRESS/LENGTH/CONTROL/INFORMATION/FCS        Where, the ADDRESS field is one byte in length and identifies        the patient station involved in the particular frame transaction        (each station has a unique address which allows the CPU and zone        controller to identify which station sent the frame); the LENGTH        field is one byte in length and contains the size of the frame,        in bytes, excluding the address and length fields; the CONTROL        field includes the command and response information used to        maintain data-flow accountability of the communication link        between the zone controller (master) and the patient station        (slave); and the INFORMATION field retains a predetermined        number of bytes of data, preferably between 1 and 145 bytes,        relating to the application data, such as, the data associated        with the activation of the nurse call button (hereinafter “the        nurse call data”). The frame-check-sequence (FCS) field,        typically one byte in length, is used to check for transmission        errors between the master and slave stations or devices.

The system of the present invention may transmit a predetermined numberof message frames, preferably between 1 and 8 frames, before anacknowledgement or response to a transmitted frame is received. As aresult, the CONTROL field is utilized to maintain data-flowaccountability of the communication link, as noted above.

Shown in table III below is the CONTROL field bit encoding for themaster and slave stations.

TABLE III CONTROL field bit encoding (master station): I-frame format::7:6:5:4:3:2:1:0: : x x : x x : 0 : : : : : : : : −> Normally act tobinary 0 : : : : : : : : : : : : :-:-:−−> N(S) : : : : : :-:-:−−−> N(R): :−−−−−> P CONTROL field bit encoding (slave station): I-frame format::7:6:5:4:3:2:1:0: : x x : x x : 0 : : : : : : : : −> Normally act tobinary 0 : : : : : : : : : : : : :-:-:−−> N(S) : : : : : :-:-:−−−> N(R): :−−−−−> P

The send sequence number N(S) (bits 1, 2 and 3) indicates the sequencenumber associated with a transmitted frame. Basically, the sequencenumber is a message counter which counts the number of message framessent to a receiving station. The receive sequence number N(R) (bits 1, 2and 3) indicates the next sequence number that is expected at thereceiving station. The receive sequence number may also serve as anacknowledgement of the previous frame. In addition, the transmittingstation maintains a send state variable V(S) which is the sequencenumber of the next message frame to be transmitted, and the receivingstation maintains a receive state variable V(R), which contains thenumber that is expected to be in the sequence number of the next frame.The send state variable is incremented with each message frametransmitted and placed in the send sequence number N(s) field in theframe.

Upon receiving a frame, a receiving station checks for a transmissionerror by comparing the send sequence number with the receive statevariable. If the frame is acceptable (i.e., the send sequence number andthe receive state variable are equal), the receiving station incrementsthe receive state variable V(R) and interpolates the variable into thereceive sequence number field N(R) in the next outbound message frame.If, on the other hand, the send state variable V(S) does not match thereceive sequence number N(R) in the message frame, the receiving stationdecrements the send state variable V(S) and retransmits the last messageframe when the next frame has to be transmitted.

To establish an interactive communication link between stations, themaster station uses the poll bit (P) to solicit a status response (e.g.,an S-frame) or an I-frame from a slave station. Generally, the slavestation does not transmit a frame to a master station until a messageframe with an active poll bit (i.e., P is set to logic 1) is receivedfrom the master frame. In the preferred embodiment, the polling rate ofthe master station is aperiodic or not fixed. The polling rate isdependent upon a number of factors such as the baud rate and the type ofmessage frame being sent by the slave station. For example, if the baudrate is 9600 and if all the slave stations respond to a poll by themaster station with an S-frame, the polling rate is approximately 20msec. However, if a slave station responds with an I-frame whichincludes 64 bytes of display data the rate (or time) before the masterstation will poll the next slave station is approximately 64 msec.Generally, at 9600 baud, one byte of data is transferred in onemillisecond.

The slave station responds to an active poll bit with an I-frame orS-frame format message frame. In the preferred embodiment, the slavestation has 15 msec. to start transmitting the responding message frameand 150 msec. to complete transmission of the frame which is identifiedby activating the Final bit (F) (i.e., F is set to a logic 1).

If the slave station fails to successfully respond to the polling frameof the master station with either an S-frame or I-frame, for apredetermined number of polls, preferably 10, that particular stationwill be marked as disconnected and will be polled at slower rate(preferably, about every 10 sec.) until the master station receives atleast one message frame from that particular slave station. When astation or other equipment connected to the system of the presentinvention are determined to be disconnected, the identity of the stationor other equipment and the room location of the equipment are stored ina problem report which can be printed on hard or soft copy via printer2724 and/or external computer 2722, shown in FIG. 4. Alternatively, theproblem report can be displayed on nurse control station display 3272shown in FIG. 32 upon the proper keying of direct select keys 3374 ofnurse control station display 3272 pursuant to menu prompts.

Referring now to Table IV below, the CONTROL field encoding for thecommands and responses used by an S-frame are shown:

TABLE IV CONTROL field bit encoding (master station): S-frame format::7:6:5:4:3:2:1:0: : x x : : : 0 1 : : : : : : : :−> Normally set tobinary 1 : : : : : : : : : : : : :-:−−> Commands: : : : : :-:−−> Binary0 - Receive Ready (RR) : : : : :-:−−> Binary 1 - Receive Not Ready (RNR): : :-:-:−−−−> N(R) : :−−−−−−−> Poll bit (P) CONTROL field bit encoding(slave station): S-format: :7:6:5:4:3:2:1:0: : : : : : : 0 1 : : : : : ::-:−> Normally set to binary 1 : : : : : : : : : : :-:−−> Commands: : :: : :-:−−> Binary 0 - Receive Ready (RR) : : : : :-:−−> Binary 1 -Receive Not Ready (RNR) : : : : : :-:-:−−−−> N(R) : :−−−−−−−> Final bit(F)

The receive ready (RR) command is used by either the master or the slavestation to indicate that it is ready to receive an I-frame and/oracknowledge previously received frames by using the receive sequencenumber. If a station had previously indicated that it was busy by usingthe receive not ready (RNR) command, the station then uses the RRcommand to indicate that it is now free to receive data (e.g., anI-frame).

As noted, receive not ready (RNR) is used by a receiving station toindicate a busy condition in response to polling by a master station.This notifies the transmitting station that the receiving station isunable to accept I-frames. The RNR command may also be utilized toacknowledge a previously transmitted frame by using the receive sequencenumber.

The commands and responses used by a U-frame are shown below in Table V:

TABLE V CONTROL field encoding (master station) U-frame format::7:6:5:4:3:2:1:0: : : : : : : 1 1 : : : : : : :-:−> Normally set tobinary 3 : : : : : : : : : :-:-:-:-:−−−−> Commands: : :-:-:-:-:−−−−> 0 -Set Init. Mode (SIM) : :-:-:-:-:−−−−> 1 - Reset lnit. Mode (RIM) ::-:-:-:-:−−−−> 2 - Test Messsge (TM) : :-:-:-:-:−−−−> 3 - Loop Back (LB): :-:-:-:-:−−−−> 4 - Broadcast (BC) : :−−−−−−> Poll bit (P) CONTROLfield encoding (slave station) U-frame format: :7:6:5:4:3:2:1:0: 1 : : :: : 1 1 : : : : : : :-:−> Normally set to binary 3 : : : : : : : : ::-:-:-:-:−−−−> Commands: : :-:-:-:-:−−−−> 0 - Set Init. Mode (SIM) ::-:-:-:-:−−−−> 1 - Reset Init. Mode (RIM) : :-:-:-:-:−−−−> 2 - TestMesssge (TM) : :-:-:-:-:−−−−> 3 - Loop Back (LB) : :−−−−−−> Final bit(F)

The set initialization mode (SIM) is used by a master or slave stationto initialize the master/slave session (or communication link). The SIMcommand puts the master and slave stations in the initialization state.Upon receiving the SIM command, the receiving station clears the sendstate variable number V(S) and the receive state variable V(R), thusclearing a retransmit buffer (not shown). The SIM command is used by astation on power-up or to clear a lock-up condition of the station. Thereset initialization mode (RIM) is used by a master or slave station toset an information transfer state. This command also serves as anacknowledgement of the SIM command.

The test message (TM) command is used to test data lines. The receivingstation responds with a LB command which carries (or echoes back) thesame data received from the message frame where the TM command wasactive. Failure of a slave station to echo back the same data receivedin the message frame causes the master station to identify the stationas disconnected and the station identity and location are added to theproblem report.

The broadcast (BC) command (bits 2-6) is used by a master station totransmit data to all slave stations. The master station sends thiscommand while the P bit is set to a logic zero and the address field ofthe message frame, noted above, contains “FF” hex.

The bit encoding for the INFORMATION field of the message frame notedabove will now be described. Preferably, the INFORMATION field consistsof four fields which identify the priority level of the message frame,the station ID, the type of message and data to augment the messagetype:

-   -   PATH/RSP_ID:REQ_ID/DATA/O

The PATH field, shown below in Table VI, may be four bytes in length andcontains routing information and frame transition priority data. Thetransition priority data identifies to the CPU the priority levelassociated with the received I-frame. As a result, the system of thepresent invention can prioritize incoming message frames so as toorganize staff responses thereto in order of priority, as will bedescribed in more detail below. The last byte of this field preferablyincludes an address expansion bit which when set to logic one identifiesthat the next byte of data is the station address field which identifieswhich slave station is sending the message frame.

TABLE VI PATH field bit encoding: :7:6:5:4:3:2:1:0: : : : : : : : : : :: :-:-:-:-:−> Station Address : : : : :-:−−−−−−> Priority: binary 2 -alarm,    binary 1 - event/control, : :-:−−−−−−>   binary 0 - data type: :−−−−−−−−> Address expansion set to logic 1 = next byte      isstation address

The RSP_ID:REQ_ID field, shown below in Table VII, containsresponse/request tag (ID) data. Upon receiving a request message (typebit is set to logic 1), the slave station sends a specific responsemessage (e.g., an I-frame). If there is no specific response, the slavestation sends generic acknowledgement typically in the form of anS-frame.

TABLE VII RSP_ID:REQ_ID field bit encoding: :7:6:5:4:3:2:1:0: : : : : :: : : : : : :-:-:-:-:−> response/request ID : : : :−−−−−−> local master:binary 1 = local master         request/response : :−−−−−−−−> type:logic 1 = request, logic 0 = response

Generally, the DATA field may be 128 bytes in length and containapplication specific data and preferably, consists of three fields:

-   -   LENGTH/DTYPE/TEXT

Where, the LENGTH field, typically 1 byte in length, contains the sizein bytes of the DTYPE and TEXT fields; the DTYPE field, typically onebyte in length, contains data codes such as the type of message beingsent, e.g., code blue; and the TEXT field which may be 126 bytes inlength, contains application specific data, e.g., message dataassociated with a particular function or station status data, which isutilized to augment the DTYPE field by identifying a textual messageassociated with the particular function identified in the DTYPE field.For example, if the DTYPE field identifies a “code blue” code, the TEXTfield will include the text which should be displayed on other stations,such as the staff station.

In the event of a failure within the CPU 2412, the system of the presentinvention also provides a fail safe feature which is activated upondetection by the nurse control stations 2414, the patient stations 2416and/or staff stations 2418. An exemplary embodiment of the configurationfor fail safe operation is shown in FIG. 7. In this configuration, failsafe bus (FSB) 3020 is connected between each patient station 2416, eachcorresponding staff station 2418 and zone indicator assembly 3022. If afailure occurs in the CPU 2412, each patient station 2416 andcorresponding staff station 2418 will fail to receive a polling signalfrom their corresponding zone controllers. As a result, each stationwill operate in a local mode utilizing the fail safe bus. When in thelocal mode, activation of any of the functions which have access to thefail safe bus will cause a response at a particular patient station, thestaff stations and at the zone indicator assembly connected to thegroup, to allow staff members in the vicinity of the station utilizingthe fail safe bus to respond.

An operational flow associated with the above described exemplary failsafe feature will be described with reference to FIGS. 7-9. As noted,upon failure of the CPU 2412, the stations associated with the system ofthe present invention operate in the local mode. In response toactivation of a fail safe device (e.g., the nurse call button 3250, thecode blue switch 3234 or the emergency switch 3232) the system firstdetermines whether the cause of the fail safe was from the activation ofnurse call button 3250 of patient control unit 3210 (shown in FIG. 9)(steps 3110 and 3120). Nurse call button 3250, code blue switch 3234and/or emergency switch 3232 are connected to patient station 2416 andprovide either a general indication to staff members that the patientneeds assistance or an emergency indication relating to the patientsimmediate health condition. Nurse call button 3250 allows the patient toindicate the need for general assistance, whereas, code blue switch 3234and emergency switch 3232 allow staff members to activate theappropriate staff response to the patient's health condition. Forexample, if the patient is experiencing a heart attack a staff memberwould activate the code blue switch.

If the cause of the fail safe was due to the activation of nurse callbutton 3250, the patient station responds by activating nurse callindicator 3222 of indicator assembly 3220 associated with thatparticular patient station and by displaying a “nurse call” message onpatient station display 3230 (step 3122). Next, the staff stations 2418(shown in FIG. 1) associated with the group of patient stations 2416respond by displaying a “nurse call” message on staff station display2422 (step 3124). Zone indicator assembly (ZIA) 3022 activates the nursecall indicator of zone indicator 3024 (e.g., indicators 1 through 8,shown in FIG. 7) associated with the particular group of patientstations (step 3126). For example, if the nurse call button is activatedby a patient station associated with group 1, the nurse call indicatorof the group 1 zone indicator 3024 associated with zone indicatorassembly 3022 will be activated. Manual reset of the patient station bya staff member responding to the call returns the FSB and the patientstations to the idle local mode (step 3128).

If the cause of the fail safe was not from the activation of the nursecall button, the fail safe system then determines if the fail safe wascaused by the activation of emergency switch 3232 (step 3130). If failsafe operation was caused by the activation of emergency switch 3232,patient station 2416 responds by activating the emergency indicatorassociated with that patient station and by displaying an “emergency”message on patient station display 3230 (step 3132). Preferably, theemergency indicator is the same indicator as nurse call indicator 3222.However, activation of indicator 3222 in the emergency mode results in ablink light at a predetermined rate in pulses per minutes (PPM) asillustrated in the table of FIG. 19. Whereas, activation of indicator3222 in the nurse call mode results in a steady lamp intensity. Second,staff station or stations 2418 associated with the subject patientstation, displays an “emergency” message on staff station display 2422,shown in FIG. 1 (step 3134). Next, zone indicator assembly 3022activates the emergency indicator of zone indicator 3024 associated withthe group with which the particular patient station belongs (step 3136).Staff members responding to the emergency call, manually reset emergencyswitch 3232 (step 3138), thus returning the fail safe system to the idlelocal mode.

If, on the other hand, the cause of the fail safe was not from theactivation of an emergency switch, then, according to this exemplaryembodiment, the fail safe operation was activated by code blue switch3234. The patient station responds to the code blue call by activatingcode blue indicator 3228 associated with patient station 2416 to whichthe code blue switch is operatively connected, and by displaying a “codeblue” message on patient station display 3230 (step 3140). Secondly,staff station or stations 2418 associated with the group of patientstations 2416, displays a “code blue” message on station display 2422(step 3142). Zone indicator assembly 3022 also activates the code blueindicator associated with the subject patient station group number (step3144). Manual reset of code blue switch 3234 by the responding staffmembers returns the fail safe bus to the idle local mode (step 3146).

Nurse Control Station

The nurse control portion of the present invention will now be describedwith reference to FIGS. 9 and 10. FIG. 9 illustrates a systemconfiguration in which peripheral equipment is connected to patientstation 2416 and in which nurse control station 2414 includes mainprocessor 3270, keyboard 3236 and nurse control station display 3272.Nurse control station display 3272 can be user programmed to performfunctions, such as initiating a code blue operational sequence, eitherthrough keyboard 3236 or direct select keys 3274. The direct select keys3274 allow staff members to select specific functions in response tomenu driven prompts.

FIG. 10 is a block diagram which illustrates hardware components fornurse control station 2414. Nurse control station 2414 includes mainprocessor circuitry 3310, keyboard circuitry 3312 and display circuitry3314. Main processor circuitry 3310 includes microprocessor 3316, suchas the 16 bit model 286 microprocessor manufactured by Chips &Technology, Inc., 2 Mbytes of memory 3318 having stored programs (e.g.,system and application programs) and communication interface 3320connected to communication ports 3322.

Preferably, communication interface 3320 and communication ports 3322are provided to facilitate data communication between zone controller2420, CPU 2412 and the nurse control station 2414. As noted above, thepreferred communication protocol includes the RS-485 serialcommunication protocol. Accordingly, communication interface 3320 isconfigured to accommodate RS-485 communication utilizing RS-485drivers/receivers which are known in the art.

Keyboard circuitry 3312 includes microcontroller 3324, such as model8052 manufactured by Intel, which includes internal memory having,preferably, 4 Kbytes of ROM and 256 bytes of RAM, keypad interface 3326which is connected to keys 3328 and facilitates communication between astaff member and the nurse control station. Communication interface 3330and communication port 3332 are provided as a data communication link tomain processor circuitry 3310. As noted, the preferred communicationprotocol includes the RS-485 serial communication protocol. Accordingly,communication interface 3330 is configured to accommodate RS-485communication utilizing RS-485 drivers/receivers which are known in theart.

Keyboard 3236 (shown in FIG. 9) includes speaker 3338, handset 3340 andmicrophone 3342 which facilitate audio communication between nursecontrol station 2414, patient stations 2416 and/or staff stations 2418,via audio controller 3344. The audio circuit portion 3410 of nursecontrol station 2414 will now be described with reference to FIG. 11,which illustrates the hardware configuration for the audio portion ofthe keyboard. As shown, audio pair 3412 from main processor 3270 ofnurse control station 2414 (shown in FIG. 9) is connected to the frontend of audio controller 3344. Preferably, the front end of audiocontroller 3344 includes a coupled 600 ohm balanced transformer 3414which isolates the internal audio circuitry of nurse control station2414 from the external audio circuits. Depending upon whether the audiosignal is being received or transmitted, the back end of audiocontroller 3344 either directs the audio signal to keyboard speaker 3338or to handset 3340, or directs the audio signal from microphone 3342 totransformer 3414.

Preferably, audio controller 3344 is a 34118 audio controllermanufactured by Motorola. Audio input signals from main processor 3270of nurse control station 2414, which pass through the audio controllerare directed to keyboard speaker 3338 via amplifier 3416 or to handset3340 via relay controller 3418 controlled by microcontroller 3324 (shownin FIG. 10). Audio generated by the nurse control station via microphone3342 or handset 3340 is transferred through relay controller 3418 toaudio controller 3344 and onto the audio pair as shown. The audio pairfrom keyboard circuitry 3312 is directed to the equipment panel via mainprocessor circuitry 3310, as shown in FIG. 10.

Display circuitry 3314 includes microprocessor 3346, such as model 8051manufactured by Intel, memory 3348 having stored programs (e.g., systemand application programs), video controller 3350 which is connected tonurse control station display 3272 and facilitates the display of thevisual communication signals. Select key interface 3352 is connected todirect select keys 3274 and is provided to identify to microprocessor3346 which direct select key 3274 has been depressed. Communicationinterface 3354 and communication port 3356 are provided as a datacommunication link to main processor circuitry 3310. As noted, thepreferred communication protocol includes the RS-485 serialcommunication protocol. Accordingly, communication interface 3354 isconfigured to accommodate RS-485 communication utilizing RS-485drivers/receivers which are known in the art.

Patient Station

The patient station portion of the present invention will now bedescribed with reference to FIGS. 4, 9 and 12, 13, 14A and 14B. Turninginitially to FIG. 9, patient station 2416 is a microprocessor controlledinterface between CPU 2412, the patient bedside equipment and peripheralequipment. The communication link between CPU 2412 and the bedside orperipheral equipment is via the master/slave communication linkdescribed above. Examples of the patient bedside equipment include heartmonitors, respirators, pulse oxymeters or I.V. pumps which include datacommunication ports to serially transmit data. Examples of peripheralequipment include patient control unit 3210, staff presence switch 3254,indicator assembly 3220, code blue switch 3234, emergency code switch3232 and/or a smoke detector (not shown). Staff presence switch 3254 ispreferably located by the door of the patient rooms and is provided toactivate indicator 3220 and to cause patient station 2416 to send amessage frame to CPU 2412 indicating the particular type of staff memberwho is present in the patient's room, as will be described in moredetail below. In addition, patient station 2416 may be operativelyconnected to a side-rail communication system (not shown) installed in aside-rail of the patient's bed, as well as bed sensors which sensewhether the patient is in the bed. Side-rail communication system may beconnected to the audio output ports 3624, shown in FIG. 13, tofacilitate audio communication at the side-rail.

FIG. 12 is a circuit block diagram for the patient station circuitry3510 installed within patient station 2416. The patient stationcircuitry 3510 includes microprocessor 3512, such as model 64180manufactured by Motorola operating at a frequency of 12.888 MHz. viacrystal 3514, 96 Kbytes of memory 3516 (e.g., 64 Kbytes of flash ROM and32 Kbytes of RAM) having stored programs, e.g., system and applicationprograms. In this exemplary configuration, the data and address buses ofthe microprocessor are connected to memory, e.g., RAM 3518 and an EPROM3520. Memory decoder 3522 is utilized to select between RAM 3518 andEPROM 3520 in response to a particular address on the address bus. Theaddress bus is also connected to a pair of latches 3524 and 3526 whichinterface the microprocessor to status indicators, the fail safe bus(FSB), the audio control circuitry, and to switches and other peripheralequipment connected to the patient station, as shown. In addition, I/Odecoder 3528 is utilized to select between either latch in response to aparticular address on the address bus. Incoming signals from the abovenoted peripheral equipment are received by buffer 3530 and thentransferred to the data-bus upon being enabled by I/O decoder 3528.

Utilizing the preferred microprocessor 3512 (i.e., the Motorola 64180),serial communication between the zone controller 2420 and microprocessor3512 or between the bedside equipment and microprocessor 3512, may beaccomplished through either one of two asynchronous serial communicationports 3532 and 3534 which are, preferably, configured to RS-485 protocolutilizing RS-485 driver/receivers (RS-485 D/R) 3536 and 3538 as shown.

FIG. 13 is a circuit block diagram for the audio portion 3610 of patientstation 2416. As shown, audio pair 3612 from an equipment panel (e.g.,audio matrix 2510 shown in FIG. 2) is connected to the front end ofaudio controller 3614. Preferably, the front end of audio controller3614 includes a coupled 600 ohm balanced transformer 3616 which isolatesthe internal audio circuitry of patient station 2416 from the externalaudio circuits. Depending upon whether the audio signal is beingreceived or transmitted, the back end of audio controller 3614 eitherdirects the audio signal to patient station speaker 3618 or to anexternal audio speaker, such as speaker 3252 of patient control unit3210, shown in FIG. 9, or directs the audio signal from microphone 3620to transformer 3616.

Preferably, audio controller 3614 is a 34118 audio controllermanufactured by Motorola. Audio input signals from audio matrix 2510which pass through the audiocontroller are directed to patient stationspeaker 3618 via amplifier 3622 and/or to audio output ports 3624 viaamplifier 3626 and relay controller 3628. Audio signals generated by thepatient station via microphone 3620 are selectively transferred throughaudio controller 3614 onto the audio pair as shown. Mute switch 3630 maybe provided to allow a staff member to manually short out the microphoneso as to prevent audio signals from being generated at the patientstation. In addition, the audio circuitry for the patient station mayinclude input audio ports 3632 which facilitate a connection betweenexternal entertainment equipment, such as a television or a radio, andaudio output ports 3624 via relay switch 3628. To illustrate, audiosignals from a television in the patient's room can be directed frompatient station 2416 to speaker 3252 in patient control unit 3210 (shownin FIG. 9) to bring the audio from the television closer to the patient.

Referring again to FIG. 9, each patient station 2416 may be coupled toexternal peripheral equipment, such as controllers, indicators and/orswitches, which provide medical instrument data and/or patient statusdata to staff members and which facilitate patient control ofenvironmental facilities within the patient's room, as will be describedbelow. FIGS. 14 a and 14 b represent an exemplary operational flow-chartof the interaction between the patient station and the bedside equipmentand between the patient station and the CPU so as to facilitatecommunication between the bedside equipment and the CPU. Initially, thepatient station monitors the inputs from the external peripheralequipment (e.g., switches) to determine if the equipment has beenactivated (steps 3710 and 3720). If a switch or other peripheralequipment is activated, a message frame associated with the activatedswitch will be stored in the memory of patient station circuitry 3510,shown in FIG. 12 (step 3722) and transferred to zone controller 2420.If, on the other hand, a switch has not been activated then the patientstation will poll the bedside equipment via serial port 3534 (shown inFIG. 12) for status or message information and interpolate fieldparameters onto the received message (step 3724 and 3726). The messageframe is then stored in patient station memory 3516 (shown in FIG. 12)and remains therein until the patient station 2416 is polled by the zonecontroller 2420 corresponding to the patient station (steps 3728, 3730and 3732).

Once polled, the patient station transfers the message frame to theS-RAM 2512 (shown in FIG. 2) of the zone controller until the last byteof the frame has been transferred (i.e., the F bit is set to logic 1)(steps 3734 and 3736). The zone controller then determines if themessage frame, received is an S-frame or an I-frame, and if the messageframe is an S-frame the zone controller acknowledges the message frameand the patient station returns to monitor the switch inputs (steps 3738and 3740). If the received message frame is an I-frame the frame istransferred to the CPU which determines whether a response to thetransmitting station is required (steps 3742, 3744 and 3746). If noresponse is required the CPU stores the received data and the patientstation returns to monitor the switch inputs, as shown. If, however, aresponse is required a response message frame is sent to the zonecontroller and stored in the S-RAM (step 3748). The zone controllerpolls the patient station and if a received ready (RR) command isreceived in return, the response message frame is transferred to andstored in the patient station (steps 3750 and 3752).

Once the response message frame is received the patient station performsthe task associated with the information in the frame (step 3754). Inaddition to sending a response message to the patient station, the CPUmay also be required to send a message frame to the nurse controlstation to alert staff members of potential faults either through toneand visual indications similar to those illustrated in FIG. 18 or byadding the information to the problem report described above (step3756).

Referring again to FIG. 9, in the preferred embodiment, patient station2416 is connected to patient control unit 3210 via data link 3246.Patient control unit 3210 includes control buttons 3248 which facilitatepatient control of the environmental facilities within the patient'sroom, via patient station 2416 and CPU 2412. Such environmentalfacilities include, for example, the television, radio, draperies andthe room lighting.

Nurse call button 3250 is provided to enable the patient to call thenurse control station or stations within the group. As noted above, thecommunication between stations is facilitated by CPU 2412 utilizing themaster/slave communication link described above.

FIG. 15 illustrates an exemplary operational flow for the patientcontrol unit 3210 in combination with patient station 2416. Uponactivation of nurse call button 3250 of patient control unit 3210 (shownin FIG. 9), patient station 2416 receives the switch activation data viadata link 3246 and buffers 3530 (shown in FIG. 12). Microprocessor 3512then interpolates field data onto the received message to form a messageframe, as described above, and stores the message frame in RAM 3518(step 3810).

Once stored in memory, the nurse call data remains therein until thepatient station is polled by the zone controller (step 3820). Oncepolled, the message frame is then transferred to the zone controller andstored in the S-RAM (step 3830). The data remains in the S-RAM until theS-RAM is polled by CPU 2412, upon which, the message frame is thentransferred to the CPU (step 3840).

Reception of the message frame in the CPU causes the CPU to begin thestation task identified in the INFORMATION field of the I-frame (step3850), to determine the message received from the patient station andprovide an appropriate response thereto (steps 3860 and 3870). For thisexample, CPU 2412 is responding to the activation of nurse call button3250 of patient control unit 3210. The initial response to theactivation of the nurse control button is to return a message frame tothe patient station to activate nurse call indicator 3222 of indicatorassembly 3220 (shown in FIG. 9). In addition, the CPU prioritizes themessage frame utilizing the transition priority data of the PATH fieldand then sends to the nurse control station or stations connected in thegroup associated with the patient station, a message frame includingtone and display data identifying the patient and the associated roomnumber (steps 3880 and 3890). At this point, the station task iscompleted and the CPU returns to the listen task. Manual reset of thepatient station by a responding staff member deactivates indicator 3222and clears the message from the nurse control station display.

Referring once again to FIG. 9 patient station 2416 may also beconnected to staff presence switch 3254, indicator assembly 3220, codeblue switch 3234 and/or emergency code switch 3232. In the configurationshown, staff presence switch 3254 is connected to patient station 2416via data link 3256 and when properly activated provides patient station2416 with a signal indicative of the type of staff member present in thepatient's room. Once activated, a message frame (e.g., an I-frame) istransferred to the CPU and an appropriate response is returned to thatparticular patient station, in a manner described above.

The responding frame from the CPU 2412 includes information to cause theactivation of an indicator in indicator assembly 3220 which correspondswith the type of staff member in the patient's room. To illustrate, ifthe staff member entering the patient room is a registered nurse (RN),that person would activate switch 3258 which in turn would activateindicator 3224 of indicator assembly 3220 via patient station 2416 andCPU 2412. If the staff member entering the room is a licensed practicalnurse (LPN), that person would activate switch 3260 of staff presenceswitch 3254, which in turn would activate indicator 3226 of indicatorassembly 3220 via patient station 2416 and CPU 2412. If, on the otherhand, the staff member entering the room is an aide, then that personwould activate switch 3262 of staff presence switch 3254, which in turnwould activate indicator 3228 of indicator assembly 3220. When the staffmember leaves the patient's room, the particular staff member switch isdeactivated so as to deactivate indicator a assembly 3220.

In the preferred embodiment, indicator assembly 3220 is a four lamplight fixture (e.g., a dome lamp) having colored lenses associated witheach lamp. The fixture is secured or otherwise positioned on the walloutside the patient's room, preferably above the doorway, to allow staffmembers in the hallway to simply look at each indicator assembly anddetermine the type of staff member in a particular patient's room, ifany. Alternatively, the indicator assembly may be any known typesufficient to provide staff members with an indication as to the type ofstaff member in a patient's room, for example, the indicator may be aLCD display which identifies the type and the name of the staff memberin the patient's room in response to information provided to the systemby the above described staff locator system, described in more detail incommonly assigned U.S. application Ser. No. 07/924,101, filed Aug. 3,1992, which is a continuation-in-part of copending U.S. patentapplication Ser. No. 07/559,196, filed on Jul. 27, 1990, the disclosureof which is incorporated herein by reference.

Code blue switch 3234 and emergency code switch 3232 are connected topatient station 2416 via data links 3264 and 3266, respectively, asshown in FIG. 9, and are provided to allow staff members to initiatecode blue or emergency responses directly from the patient's room. Asnoted above, code blue and/or emergency code procedures may also beinitiated from nurse control station 2414. Initiation of the code blueresponse procedure at a patient station 2416 will result in thefollowing occurrences. Initially the code blue data signal received fromthe code blue switch is stored in the patient station memory as amessage frame, in a manner described above. The microprocessor 3512(shown in FIG. 12) in the patient station 2416 then waits to be polledfrom the zone controller 2420 before transferring the data to the zonecontroller. Once polled by zone controller 2420 the message frame istransmitted to the zone controller and stored in the S-RAM 2512 untilthe S-RAM is polled by CPU 2412. Once the message frame is receivedwithin the CPU the message frame is prioritized and the station taskassociated with the data within the INFORMATION field of the messageframe is initiated.

An example of a station task performed by the CPU in response to theactivation of a code blue switch will be described below. Initially CPU2412 determines the message type received from zone controller 2420.Next the CPU performs whatever function is associated with the message,in this example the message relates to the code blue function. Inresponse to the code blue function, the CPU 2412 sends to the particularpatient station an I-frame which includes data to cause activation ofparticular peripheral equipment as well as devices within the patientstation 2416, e.g., a tone code and an indicator assembly activationcode. Next CPU 2412 determines which staff station or stations 2418 andwhich nurse control station or stations 2414 are grouped with thesubject patient station 2416. Thereafter, CPU 2412 sends to eachassociated staff station an I-frame including message data to display“code blue” on staff station display 2422 of staff station 2418. NextCPU 2412 sends a message to the ZIA 3022, shown in FIG. 7, to activatethe proper indicator associated with the patient station group in amanner similar to that described above with reference to fail safe bus3020.

The CPU 2412 then sends an I-frame to each nurse control station groupedwith the patient station to display the room number and identity of thepatient subject to the code blue function, on the display of the nursecontrol station. The CPU 2412 then sends to the nurse control station anI-frame including appropriate control signals associated with thepatient station message. Once the above steps are accomplished thestation task is completed and the CPU 2412 returns to the listen task.

The system of the present invention may also be configured to monitormedical equipment being used to treat the patient (i.e., bedsideequipment). Such bedside equipment may be connected to communicationport 3534 (shown in FIG. 12) of patient station 2416. In instances wherethe serial data from the bedside equipment is not configured for RS-485protocol, serial data converter 2520 (shown in FIG. 2) may beinterconnected between serial port 3854 of patient station 2416 and theserial port of the bedside equipment. Typically, the serial port of thebedside equipment is configured to operate with RS-232 protocol, thus,serial data converter 2520 would be an RS-485 to RS-232 converter whichis known in the art.

Examples of the above described bedside equipment are shown in FIG. 9.As shown, a heart rate monitor 3280 is connected to patient station 2416via data link 3282, which as noted above is operatively connected tonurse control station 2414 via zone controller 2420 and CPU 2412. Thepatient station (acting as a master station) polls heart rate monitor3280 (operating as a slave station) to verify that the patients heartrate falls within the proper range as determined by the monitor. Thezone controller periodically polls patient station 2416, as describedabove for an S-frame or an I-frame message frame. Typically with respectto this example, if no fault is detected the patient station willrespond to the polling of the zone controller with an S-frame indicatingproper operation of heart rate monitor 3280. However, a fault detectedin monitor 3280 will be stored in RAM 3518 of patient station circuitry3510 (shown in FIG. 12) along with the appropriate field data in theform of an I-frame, and the I-frame is transferred to zone controller2420 and CPU 2412 in a manner described above. The CPU then analyzes theI-frame and an appropriate alarm sequence is initiated to notify staffmembers at nurse control station 2414 of the detected fault.

As another example, an intravenous (IV) pump 3284 is connected topatient station 2416 via data link 3286, which as noted above isoperatively connected to nurse control station 2414, via zone controller2420 and CPU 2412. In this example, the IV pump is periodicallymonitored by patient station 2416 to ensure the flow rate of the pump isappropriate. If a failure is detected, a message frame including theerror message is transferred to CPU 2412 in a manner set forth above.The CPU the initiates an appropriate alarm sequence, such as displayinga message on the monitor of nurse control station 2414, that the IVcontainer is empty and needs to be changed. It should be noted, thatnumerous other types of bedside equipment may be monitored by the systemof the present invention, including respirators and heart monitors.

Transmitter 3290 is hardwired to the bedside equipment, e.g., heart ratemonitor 3280, and is provided to enable a central computer system todetermine what room or other area of the health care facility thebedside equipment is located and to transmit operation data generated bythe bedside equipment, such as status data or other data associated withthe operation of the equipment. In this configuration, transmitter 3290transmits an identification signal and the operation data to an IRtransceiver which is in communication with the central computer througha network server as described in application Ser. No. 07/924,101. Thecentral computer determines which transceiver received theidentification signal of the bedside equipment and transfers thelocation data of the equipment and the operation data to CPU 2412 viadata link 2728 (shown in FIG. 4). Transmitter 3290 may be a radiofrequency transmitter operating at a frequency of approximately 300 MHz,which are available from Dallas Semiconductor, Inc.

Staff Station

Referring again to FIG. 1, staff station 2418 is similar in design topatient station 2416. In the preferred embodiment, staff station 2418may be configured, in the initial system configuration setup, to operatein a “duty” mode or a “staff” mode. In the “duty” mode staff station2418 provides patient call indications on staff station display 2422, aswell as facilitating communication with nurse control station 2414. Inthe “staff” mode staff station 2418 facilitates communication with nursecontrol station 2414.

FIG. 16 illustrates hardware configurations for the staff stationcircuitry 3910 installed within staff station 2418. The staff stationcircuitry 3910 includes microprocessor 3912, such as model 64180manufactured by Motorola operating at a frequency of 12.888 MHz. viacrystal 3914, 96 Kbytes of memory 3916 (e.g., 64 Kbytes of flash ROM and32 Kbytes of RAM) having stored programs, e.g., system and applicationprograms. In this exemplary configuration, the data and address buses ofthe microprocessor are connected to the memory, e.g., RAM 3918 and anEPROM 3920. Memory decoder 3922 is utilized to select between RAM 3918and EPROM 3920 in response to a particular address on the address bus.The address bus is also connected to a pair of latches 3924 and 3926which interface the microprocessor to status indicators, the fail safebus (FSB), the audio control circuitry, and to switches and otherperipheral equipment connected to the staff station, as shown. Inaddition, I/O decoder 3928 is utilized to select between either latch inresponse to a particular address on the address bus. Incoming signalsfrom the above noted peripheral equipment are received by buffer 3930and then transferred to the data-bus upon being enabled by I/O decoder3928.

Utilizing the preferred microprocessor (i.e., the Motorola 64180),serial communication between the zone controller and the microprocessormay be accomplished through asynchronous serial communication port 3932which is, preferably, configured to RS-485 protocol utilizing RS-485driver/receiver (RS-485 D/R) 3934 as shown.

FIG. 17 illustrates hardware configurations for the audio portion 4010of staff station 2418. As shown, audio pair 4012 from an equipment panel(e.g., audio matrix 2510 shown in FIG. 2) is connected to the front endof audio controller 4014. Preferably, the front end of audio controller4014 includes a coupled 600 ohm balanced transformer 4016 which isolatesthe internal audio circuitry of staff station 2418 from the externalaudio circuits. Depending upon whether the audio signal is beingreceived or transmitted, the back end of audio controller 4014 directsthe audio signal to staff station speaker 4018 or directs the audiosignal from microphone 4020 to audio matrix 2510 via audio controller4014.

Preferably, audio controller 4014 is a 34118 audio controllermanufactured by Motorola. Audio input signals from audio matrix 2510which pass through the audio controller are directed to staff stationspeaker 4018 via amplifier 4022. Audio generated by the staff stationvia microphone 4020 is selectively transferred through audio controller4014 onto the audio pair as shown. Mute switch 4024 may be provided toallow a staff member to manually short out the microphone so as toprevent audio signals from being generated at the patient station.

System Functions

The patient care and communication system of the present invention maybe programmed to perform numerous operations associated with patientcare and communications within a hospital or other health care facility.The following functions are exemplary of the numerous types of featuresand the functional flow (or data exchange) between the differentstations, the CPU and the zone controller utilize the above describedpreferred master/slave communication link.

a. Call Priority

Message frames usually in the form of an I-frame originated by a nursecontrol station, a patient station and/or a staff station areinterpreted by CPU 2412 and assigned a priority level based upon thetype of message frame received (i.e., the DTYPE field of the INFORMATIONfield contains the message type which corresponds to the priority levelthat will be assigned to the frame). In addition, the message associatedwith the TEXT field of the message frame is displayed on nurse controlstation display 3272 of a nurse control station 2414 in order ofpriority level. The priority levels are preprogrammed during the initialset-up of the system configuration, but may be altered by staff membersat nurse control station 2414 via keyboard 3236 or direct select keys3274 (shown in FIG. 9). The highest priority call will be displayedfirst and other calls will follow in descending order according to thepriority level.

Preferably, each call originated has specific audible and visualsignaling based on the call priority level which are distributed to thenecessary nurse control stations, zone indicator assembly, patientstations and/or staff stations via CPU 2412 and their respective zonecontroller. FIGS. 18-20 represent tables illustrating exemplaryembodiments of call priority levels, their associated visual and toneindications which are generated at either the nurse control station, thepatient station and/or the staff station. FIG. 18 illustrates thepreferred visual display which appear on nurse control station display3272 and the tones generated at speaker 3238 (shown in FIG. 9) inresponse to the various priority levels. For example, in response to theactivation of code blue switch 3234 (shown in FIG. 9) CPU 2412 willtransmit to nurse control station 2414 a message frame instructing thenurse control station to display on the nurse control station display3272 a flashing arrow directed at a direct select key 3274 to indicatewhich key will enable the staff member to connect the audio of the nursecontrol station to the audio of the patient station and respond to thecall. The arrow will flash at a rate of approximately 120 pulses perminute (PPM). In addition, the room number and bed number associatedwith the patient station to which the code blue switch is connected andthe “CODE BLUE” message will be displayed on nurse control stationdisplay 3272. An audible tone at the rate of 120 PPM will also begenerated at speaker 3238 of nurse control station 2414.

The preferred response at patient station 2416, shown in FIG. 19, to theactivation of the code blue switch will be to pulse a station call andbed call placement LED indicators (not shown), which may be positionedon the front panel of patient station 2416, at a rate of 120 PPM, and topulse a code blue indicator of the corresponding group indicatorassembly 3024 via ZIA 3022 (shown in FIG. 7) at a rate of 120 PPM.

The preferred response at staff station 2418, shown in FIG. 20, to theactivation of the code blue switch will be to pulse an incoming call LEDindicator which may be positioned on the front panel of staff station2418, at a rate of 120 PPM, to display on staff station display 2422(shown in FIG. 1) the room and bed number associated with the patientstation to which code blue switch 3234 is connected and to display the“CODE BLUE” message; to pulse a blue indicator of the correspondinggroup indicator assembly 3024 via ZIA 3022, at a rate of 120 PPM; and togenerate an audible tone at the rate of 120 PPM at speaker 4018 of staffstation 2413 (shown in FIG. 1).

b. Nurse Follow

The nurse follow feature allows a staff member to selectively directincoming calls to a particular nurse control station to selected patientstations and/or staff stations. To illustrate, this feature may allowthe staff member to program the nurse control station to distributeincoming calls to a single patient station, to patient stations whereparticular staff members have activated respective staff presenceswitches (e.g., switch 3254, shown in FIG. 9) and/or to all patient orstaff stations assigned to the group associated with the particularnurse control station. Thus, when a staff member is required to leavethe area of a nurse control station, incoming calls to the nurse controlstation can be routed to locations where appropriate staff members canrespond to the call.

In operation, a staff member attending nurse control station 2414 mayutilize direct select keys 3274 (show in FIG. 9) in response to menudriven prompts to configure the system to operate in the nurse followmode. In the nurse follow mode, calls which are directed to the nursecontrol station 2414 via CPU 2412 and corresponding zone controllers2420 will automatically be routed to the station or stations selected bythe staff members or to stations in locations where that staff member orother staff members are determined to be present by staff locator system2428 (shown in FIG. 4 and described in U.S. application Ser. No.07/924,101).

For example, if the staff member selects the nurse follow feature whichroutes incoming calls to patient stations where the RN switch 3258 ofstaff presence switch 3254 (shown in FIG. 9) has been activated, CPU2412 will direct the incoming call to the nurse control station to anyroom in the group where switch 3258 of staff presence switch 3254 hasbeen activated.

As another example, CPU 2412 of the patient care and communicationsystem interacts with the central computer system of staff locatorsystem 2428, shown in FIG. 4. In this configuration, the identificationbadges are in communication with the central computer system in a mannerdescribed in application Ser. No. 07/924,101, which is incorporatedherein by reference. In particular, FIGS. 4 and 17 c of thatapplication, show the identification badge 1111, which is worn by thestaff member, continually transmits the identification signal (of thestaff member) and the central computer system continually monitors theidentification signal to update the location of the badge (and the staffmember). The location information of the staff member is transferred toCPU 2412 via data link 2726 (shown in FIG. 4) which may be any knowntype of communication link utilized to facilitate communication betweencomputer systems. Therefore, when a call is directed to a nurse controlstation 2414 programmed to operate in the nurse follow mode, CPU 2412will route the incoming call to a station (either 2416 or 2418)positioned nearest the detected location of the staff member. In analternative embodiment, a staff member attending the nurse controlstation may want to route incoming calls to locations of other staffmembers. In this embodiment, the nurse control station can be programmedin the nurse follow mode to route the incoming calls intended for nursecontrol station 2414, to stations where the other staff members havebeen detected by the staff locator system.

c. Voice Paging

The voice page feature allows staff members to communicate to selectedpatient and/or staff stations from the nurse control station. Toillustrate, this feature allows a staff member to communicate to allstaff members who have activated staff presence switches associated withthe nurse control station (i.e., within the same group) and all staffmembers in areas where staff stations are located. FIG. 21 illustratesan exemplary operational flow for the voice paging feature of thepresent invention. Initially, the staff member desiring to page allstaff members within the assigned group, programs nurse control station2414 via direct select keys 3274 (shown in FIG. 9) which activate menudriven functions (step 4410). The menu driven instructions from thenurse control station are then transferred to the CPU via zonecontroller 2420 in a manner described above (step 4420). The CPUanalyzes the instructions, e.g., determines the identification of thepatient and/or staff stations and their associated zone controllers andthe CPU performs the function associated with the received message frame(step 4430, 4440 and 4450). Thereafter, the CPU causes the audioconnection between each station and the nurse control station andnotifies the paging staff member to begin talking (steps 4460 and 4470).

Alternatively, the voice paging feature may utilize staff locator system2428, shown in FIG. 4 to determine the location of a staff member ormembers so that the staff member attending nurse control station 2414may communicate with the patient and/or staff stations nearest to eachstaff member or members being paged.

d. Room Monitoring

The room monitoring feature allows staff members attending a nursecontrol station 2414 to activate the audio system of either a selectednumber of patient stations 2416 or to manually step or automaticallyscan through each patient station 2416 in each room associated with thestation grouping, described above, in a predetermined order for apredetermined period of time so as to activate microphone 3520 ofpatient station 2416, enabling staff members to listen for sounds ofdistress or other uncharacteristic noises so as to check on the wellbeing of a patient or patients. Preferably, the predetermined order formonitoring rooms is from the lowest room number to the highest and thepredetermined period of time is approximately ten seconds. In operation,the staff member attending nurse control station 2414 configures thesystem for automatic room monitoring by depressing direct select keys3274 of nurse control station display 3272 in response to menu drivenprompts. Once configured for automatic monitoring, CPU 2412 sends amessage frame to each patient station in the above noted order toactivate microphone 3620 (shown in FIG. 13) of audio circuitry 3610, viaaudio controller 3614, for a period of ten seconds to allow theattending staff member to listen for distress noises and otheruncharacteristic noises.

Diagnostics

The system of the present invention also provides diagnostic featureswhich continuously monitor system components. As noted above, systemfaults are communicated to the nurse control station and/or to the staffstation and added to the problem report. Hard and/or soft copies of theproblem report may be obtained from printer 2724 and/or externalcomputer 2722 (shown in FIG. 4) or the problem report may be displayedon nurse control station display 3272 when the “problem reports” featureis selected by direct select keys 3274 shown in FIG. 9.

In addition, the operation of selected periphery devices in thepatient's room are continuously monitored and any failures are broughtto the attention of the staff member at a nurse control station withinthe group. For example, the wiring to code blue switch 3234, the smokealarm and/or the nurse call button 3250 on patient control unit 3210 maybe monitored for damaged to the wires between such periphery devices andpatient station 2416.

FIG. 22 shows the hardware components for patient control unit 3210which is connected to patient station 2416. Preferably, the wiring istested by microprocessor 3512 (shown in FIG. 12) activated signals incombination with the wire test circuitry 4510. Wire test circuit 4510includes resistor 4512 and field effect transistor (FET) 4514 which areconnected between call wire 4516 and nurse call wire 4518, as shown. Inthis configuration, microprocessor circuitry 3510 of patient station2416, shown in FIG. 12, periodically turns on FET 4514 via call wire4516 therefore completing the ground path connecting call wire 4516 andnurse call wire 4518. Microprocessor 3512 then interrogates nurse callwire 4518 via buffer 3530 (shown in FIG. 12) in response tomicroprocessor driven instructions, so as to perform a continuity checkof the nurse call feature of patient control unit 3210. Preferably, theperiod between each wire test is two seconds. Wire test circuit 4510 maybe utilized to perform wire tests between any periphery equipment andthe processor associated with the station to which the peripheralequipment is connected. In the event the continuity check fails, afailure alarm sequence is initiated to notify staff members of the wirefailure and which wire in which periphery device has failed.

The patient care and communication system of the present invention alsoincludes external diagnostic device 2570 connected to serial dataconverter 2520, as shown in FIG. 2. Preferably, external diagnosticdevice 2570 is a modem provided to facilitate external diagnostics ofthe patient care and communication system of the present invention, viaconverter 2520 and zone controller 2560. External diagnostic device 2570allows a technician or other service personnel to remotely verify andupdate the configuration of the system in a manner similar to thatperformed by staff members attending a nurse control station. Inaddition, the external diagnostic device 2570 allows the technician orother service personnel to view the system problem report which, asnoted above, includes information as to which stations or equipment arenot operational.

Stations with PBX Telephone Interface

An alternative embodiment for the system configuration is shown in FIGS.23 and 24. In this embodiment a private-branch exchange (PBX) 2430 isconnected to nurse control stations 2414, patient stations 2416 andstaff stations 2418 for providing staff-to-staff, staff-to-patientand/or external telephone communications for the hospital environment.The PBX 2430 also connects to a plurality of telephones throughout thefacility and to or from external telephone lines of the telephone localexchange or central office. The components of a PBX for processing dataand controlling the telephone operations are well known. The PBXaccording to the present invention includes a processor, associatedmemory and stored programs. The preferred PBX according to the presentinvention is the IDS-228, manufactured by EXECUTONE Information Systems,Inc. Each station is provided with a PBX interface which facilitates PBXtelephone or voice communications therebetween. System datacommunications are accomplished in a manner described above utilizingzone controllers 2420 and the above described protocol.

FIG. 25 is a circuit block diagram of the patient station 2416 accordingto the alternative embodiment, which includes a telephone circuit 4610,which in turn connects to the PBX 2430. The patient station furtherincludes a receiver unit 4800 for sensing or receiving signalstransmitted from the portable badges. As shown, the patient station 2416is a microprocessor controlled interface having similar system datacommunications as the patient station described above with reference toFIGS. 4, 9 and 12-14 b. Further, the telephone circuit 4610 facilitatestelephone communication between a patient via patient station controlunit 3210, shown in FIG. 23, and the internal and external telephonesystems via PBX 2430, shown in FIG. 24.

According to the alternative embodiment, the receiver unit 4800 receiveswireless electromagnetic transmissions, preferably infrared andfrequency modulated (FM), from a portable transmitter. The transmissionsfrom the portable transmitter include transmitter ID signals. Thereceiver in turn forwards an information packet including the receivedtransmitter ID signals to the central processing unit 2412 whichdetermines the identity and location of the transmitter. The informationpacket from the receiver 4800 is preferably forwarded to the centralprocessing unit 2412 through zone controller 2420. Alternatively, theinformation packet is forwarded to the PBX 2430 through telephonecircuit 4610. According to the alternative embodiment of the presentinvention, the PBX 2430 is capable of processing the information packetfrom the receiver 4800 to determine the identity and location of thetransmitter, both independently from or as a shared resource of thecentral processing unit 2412. Of course, the information packet from thereceiver 4800 may be forwarded to the central processing unit 2412 viathe PBX 2430 or vice versa.

Typically, telephone voice and data communication between each stationand the PBX 2430 is in the form of message frames which are divided intofields, e.g., a data field and a control field. As an example, the datafield associated with voice data to the station is approximately 64kilobits in length and the control field is approximately 2 kilobits inlength. The control field includes a sync bit for synchronizingcommunications between the telephone and the PBX. The preferredtransmission rate for data is 19.2 kilobits per second.

According to the alternative embodiment, a robbed bit signalingtechnique is utilized for transferring data from the patient, staff ornurse control station to the PBX. For example, utilizing this technique,one bit within every fourth transmission of the voice/data stream isutilized for the transmission of the system data. Thus the effectivedata transmission rate of the control data is approximately 2 kilobitsper second.

FIGS. 26-28 illustrate typical system timing and format diagrams for thecommunication of data frames between the stations of the presentinvention and the PBX 2430. As shown in FIG. 26, the data transmittedfrom the microprocessor or microcontroller (hereinafter identified as“microprocessor”) within each station is configured in a 16 bit paralleldata word on the microprocessor data bus, which is preferably framed byone (1) start bit and seven (7) stopbits. Communications with the PBXsystem, on the other hand, are in a serial mode, therefore, the 16 bitparallel data word is converted to a serial data stream in the telephonecircuit within each station, via parallel-to-serial converter 4620,shown in FIG. 25. In addition, a synchronization bit (sync bit) is addedinto each microprocessor data frame to maintain clock alignment betweenthe PBX and the station.

Preferably, telephone voice transmissions between the PBX and thetelephone are in the PCM format which may utilize the primary, secondaryor both channels. As shown in FIG. 25, PCM CODEC 4630 compresses thevoice information into PCM format. Transmitter conditioner 4640amplifies and modulates each frame for transmission to the PBX 2430. Theprimary channel is preferably a 64 kilobits channel used to transfercontrol information to and from peripheral devices (e.g., the PBX), asynchronization bit for the hardware, and the voice signal. Thesecondary channel is also a 64 kilobit channel which is utilized totransfer EIA data and controls for serial communications, such as forRS-232 applications.

FIGS. 27 and 28 illustrate exemplary message frame formats and timing inan expanded form for telephone voice and data information between eachstation and the PBX. As shown in FIG. 27, data from the microprocessoris in a 16 bit parallel format and is framed by one start bit and sevenstop bits to form the microprocessor (uP) data frame, where each uP dataframe is approximately 8 ms in length. Telephone voice, data andinformation packet including transmitter ID from microprocessor 3510,shown in FIG. 25, is then converted to a serial data bit stream viaparallel-to-serial converter 4620 which then transfers the serial.signal to transmitter conditioner 4640. Transmitter conditioner 4640amplifies and modulates the PCM signal for transmission to the PBX 2430via the 4-pair telephone wire.

An exemplary embodiment of the format and timing of data transmittedfrom the PBX to a telephone, patient station, staff station or nursecontrol station is shown in FIG. 28. Return telephone voice and datainformation, e.g., data to notify a called party who called, isgenerated in the PBX and is formatted into an 8 bit PBX data frame ofapproximately 8 ms. in length (i.e., 1 ms/bit). Two of the eight bitsare designated as auxiliary. A sync frame is then added into each bitportion of the PBX data frame and the resultant signal is conditionedfor PCM transmission to a station, e.g., either nurse control station2414, patient station 2415 and/or staff station 2418.

Referring again to FIG. 25, the PCM signal received at a station fromPBX 2430 is processed through a waveshaper and conditioner 4650. Thewaveshaper and conditioner 4650 converts the received signals from thePCM format to a serial digital format, recovers the synchronizationclock to sync the timing via phase-locked loop 4670, and recaptures thetelephone voice and data information. Data retrieved by the receiverwaveshaping and conditioning 4650 is transferred to serial-to-parallelconverter 4660 which converts the data from a serial format to aparallel format for interaction with microprocessor 3512 and PCM CODEC4630. PCM CODEC 4630 decodes the digital voice information forsubsequent transmission of analog voice information to control unit 3210for broadcast through speaker 4720, shown in FIG. 29.

According to the alternative embodiment, infrared sensitive photodiodes4810 of receiver 4800 senses infrared transmissions from an infraredtransmitter and converts the infrared signals to electrical signals.Waveshaper and conditioner 4820 conditions and amplifies the electricalsignals and FM receiver 4330 demodulates the data for the carrier signaland serially transfers the received data to an I/O port ofmicroprocessor 3512. According to the alternative embodiment of theinvention, the receiver 4800 is capable of receiving infraredtransmissions from portable transmitters at a distance of around 30 feetor greater from the station. Microprocessor 3512 receives the serialdata from the FM receiver 4830 and extracts the transmitter IDinformation. The extracted information is reformatted and forwarded inan information packet to the PBX 2430 or the central processing unit2412 for further processing and location determination.

FIGS. 33-38 show the components of an exemplary wireless electromagnetictransmitter, such as an infrared transmitter, which may be incorporatedinto a badge unit 5110, as well as various other known portable mediums,and a personnel or patient card 5200. The badge units are preferablyadapted to be worn by staff members and/or patients within a health carefacility using clip 5120, or adapted to be releasably attached tostationary or mobile devices or equipment using a suitable adhesive,identified as 5130, or like mediums such as VELCRO®. In instances wherethe transmitters are attached to devices or equipment, the transmitterpermits tracking of such devices so as to permit staff members to easilydetermine the location of the device for retrieval and allow the badgesto transmit information regarding the status of the equipment, such ason/off status. The badge unit includes a microcontroller 4900 forcontrolling the operations of the badge and a transmitter 4910 fortransmitting signals to a plurality of receivers. The microcontroller4900 is preferably a single integrated circuit chip which includes aprocessor and RAM and ROM memory.

Preferably, the transmitter is enclosed in a housing which is shaped andsized like an ordinary credit card or smaller. FIGS. 34-36 illustratethe side, top and bottom views, respectively, of the badge housing. Thehousing 5140, as shown, is approximately 3.8 inches in length, 2.27inches in width and 0.39 inches in thickness. The housing 5140 includesa slot 5150 which is configured to receive personnel card 5200 shown inFIGS. 37 and 38. Badge unit 5110 also includes electrical contacts 5160which are connected to microcontroller 4900 of badge unit 5110 as shownin FIG. 33. Contacts 5160 are provided to engage corresponding contacts5220 on the personnel card 5200 for data communications therebetween, aswill be described in more detail below. A more detailed description ofthe badge unit is described in commonly assigned U.S. patent applicationSer. No. 08/087,394, filed Jul. 2, 1993 which is incorporated herein byreference.

The ROM memory may be of the programmable type and stores softwareprograms for operating the badge. These programs include: programs forcontrolling the transmitter 4910; for monitoring operational parameters;and for interfacing with external devices. The RAM memory includes adatabase for storing information including an identification code of thebadge and operational parameters which are retrieved and monitored bythe processor for operating the badge unit. The database may furtherinclude information regarding the person associated with the badge,e.g., medicine which the person is allergic to. The database may alsoinclude information relating to an associated object, e.g., medicalequipment and its operating parameters or data.

Functions associated with the processor include: logical and arithmeticoperations and coordination of data transfer to and from themicrocontroller 4900. In the preferred embodiment, the processor alsoperforms a fail safe function which periodically transmits a message tothe central processing unit 2412 via patient station 2416 and PBX 2430.The periodic message, e.g., a fail safe code, is provided to inform thecentral processing unit 2412 that the badge is operational. Thus, if themessage is not received from the badge unit, the central processing unit2412 determines that either the badge unit has malfunctioned or that thebadge unit is not within the operational confines of the system of thepresent invention, e.g., a staff member has left the hospitalenvironment. The identification code of the badge may be utilized as thefail safe code which is periodically transmitted.

A microcontroller such as the PIC®16C5X manufactured by MicrochipTechnology, Inc. is used in the preferred embodiment of the presentinvention. It is apparent to one skilled in the art that anymicrocontroller having equivalent performance characteristics andsimilar in size may also be used.

An edge connector 4920, shown in FIG. 36, facilitates interfacing to thecomponents of the badge from an external device, such as diagnosticmedical equipment (not shown). The edge connector 4920 preferably hasfour connections which include a “Bidirect I/O” connection to aninput/output port of the microcontroller 4900 for bidirectionalcommunication with the microcontroller 4900. Data can be written into orread out of the microcontroller memory by the external device (“theBase”) through this connection. The Base preferably includes processing,storage and interfacing capabilities for communicating with andtransferring information between the Base and the badge. A standardserial interface protocol such as RS232 may be used for suchcommunications. In instances where the badge unit is connected to amedical device, such as a heart monitor, connector 4920 is connected tothe serial port of the heart monitor and status data, e.g., the heartrate of the patient being monitored, of the heart monitor is transferredto microcontroller 4900 and then transmitted via transmitter 4910 to thepatient station receiver described above, or to an independent wirelessreceiver which will be described hereinbelow.

Another connection associated with edge connector 4920 is an “In-Base”connection which is monitored by the microcontroller 4900. An activesignal at the “In-Base” input indicates that the microcontroller is torelinquish control to the external device. The badge according to thepresent invention is powered by a battery, which preferably is made oflithium. Other battery designs such as NICAD (nickel cadmium)rechargeable type or solar cell may also be used. The charge battery LEDindicator 4950 provides a visual indication of the charge status of thebattery. The charge battery circuitry may also be connected tomicrocontroller 4900, as shown in FIG. 33, so that the microcontrollercan transfer the battery charge status information to the patientstation via transmitter 4910. Alternatively, microcontroller 4900 mayinclude a software counter which counts the number of transmissions fromtransmitter 4910 to determine the battery charge status of the badge.After a predetermined number of transmissions, microcontroller 4900transmits to the patient station the battery charge status information,e.g., the battery power is low. Preferably, the predetermined number oftransmissions is based on the average power used per transmission andthe statistical life of the battery.

Another input of the edge connector 4920 may be used to recharge thebattery. The fourth connection of the edge connector 4920 is a spareinput/output. The badge includes a light sensitive LED 4930 forproviding wireless means for inputting data to the microcontroller 4900by serially strobing data with a light source into the microcontroller4900.

An oscillator 4940 is connected to the microcontroller 4900 forproviding an oscillation signal, which in turn generates a clock signalfor clocking or timing purposes. In the preferred embodiment, theoscillator 4940 includes a resistor/capacitor combination for providinga clock which operates at a frequency of around 455 kilohertz. Due tovariations in the tolerances of the resistor/capacitor combination, theclock rate for each badge unit will vary from one badge to anothersubstantially around 455 kilohertz. The microcontroller 4900 includes aprescaler for providing time and clock signals.

A mode select switch 4960, preferably a normally open pushbutton switch,facilitates manual communication to the microcontroller 4900 forfunctions such as mode select or transmission of a preselected message.Typically, the function selected is dependant upon the number andsequence of button pushes. Examples for the modes of operation include:“erase memory” for erasing the contents of the RAM memory; “turn-offtransmitter” for disabling any transmission from the badge; “cardreinsertion” for turning off the badge when the personnel card isremoved until a card is reinserted; “ID code change” for changing the IDcode to a special preselected code to signal an abnormal condition; and“disable counters” mode, which overrides parameter operations forturning off or disabling the badge and maintains badge operations.

Badge units which are worn by patients or releasably affixed to astructure which is proximal to the patient as shown in FIG. 39, mayinclude a patient select switch or member 4970 shown in FIG. 36 whichfacilitates patient control of the environmental facilities within thepatient's room and the nurse call function. Preferably, the patientselect switch is a normally open pushbutton switch which controls suchenvironmental facilities or the nurse call function via transmitter 4910of the patient station 2416 and CPU 2412 utilizing the communicationtechniques described above. Such environmental facilities include, forexample, the television 5310, radio, draperies, thermostat 5320 or theroom lighting. Selection and control of a particular environmentalfacility or the nurse control function is dependant upon the number andsequence of button pushes. Data transmissions between the badge unit andthe patient station is similar to the infrared data transmissionsdescribed above.

In an alternative embodiment shown in FIGS. 39 and 40, the badge unitmay interface with an independent wireless electromagnetic receiver,preferably infrared receiver 5330. In one embodiment, each wirelessreceiver is located within the patient room and connected to acontroller 5370 which responds to control data received from receiver5330 to control the environmental facilities. In another embodiment,each wireless receiver is connected to either the central processingunit 2412 through zone controller 2420 or to the PBX 2430. In thisembodiment, central processing unit 2412 or PBX 2430 will respond to thecontrol data in a similar manner as controller 5370 and communicationsbetween the independent receiver and the central processing unit 2412 orthe PBX 2430 is similar to the above described communications relatingto receiver 4800, shown in FIGS. 23 and 25. As shown in FIG. 40,infrared light sensitive diode array 5340 receives infrared signals,preferably frequency modulated infrared signals, transmitted from badgeunits 5140 within approximately 30 feet of the receiver. Waveshaping andamplifier network 5350 conditions and amplifies the signals generated bythe diode array 5340. FM receiver 5360 demodulates the control data fromthe carrier signal and serially transfers the received control data tocontroller 5370.

Referring to FIG. 40, each independent infrared receiver 5330 isconnected to a controller 5370 having a processor, memory and storedprograms. Controller 5370 receives the serial data from FM receiver 5360and extracts the badge control data, e.g., the number and sequence ofbutton pushes of the patient select switch 4970. The extracted controldata is processed by controller 5370 to determine which environmentalfacility is being selected and which control function is to beperformed. Preferably, each environmental facility is assigned anidentification code which is stored in the memory of the controller. Inthis configuration, when control data is received by the controller, thecontroller determines which identification code has been received toselect the desired environmental facility. For example, if thecontroller determines that the television has been selected, thecontroller may then be instructed to turn the television on or off, tochange the channel or to increase or decrease the volume. A moredetailed description of the FM infrared receiver and its operation isdescribed in U.S. Pat. No. 4,977,519 to J. Crimmins, which isincorporated by reference.

Referring to FIG. 41, an alternative embodiment of the patient roomconfiguration of FIG. 39 is shown. In this embodiment, all devices whichwere connected by wires, e.g., the patient station 2416 and thermostat5320 shown in FIG. 39, except the ceiling wireless receiver 5330, havebeen made wireless and portable. All functions performed by the deviceswithin the room as shown in FIG. 39 are performed by the wireless units.The wiring installation of the system as shown in FIG. 41, simplyrequires the wiring installation of wireless receiver 5330 within eachpatient room, connecting the wireless receiver to a central computer,controller or to the PBX. Generally, previously wired devices forcontrolling the environment are replaced with a unit with an integraltransmitter. For example, thermostat 5320 includes a wirelesstransmitter 5322. Thermostat 5320 measures the ambient temperaturewithin the room and transmits the temperature data to receiver 5330 viatransmitter 5322. In addition, the patient may control otherenvironmental facilities within the room, e.g., a television, via badge5140 as described above. As shown in FIG. 41, the thermostat 5320 andthe badge 5140 are placed on a night stand within the room and proximalto the patient.

The functions of the patient station 2416 and pillow speaker 3210 may beperformed by an enhanced badge unit having components as shown in FIG.42. The enhanced badge unit includes voice and display communicationcontrols for communicating information previously performed by thepatient station 2416 and pillow speaker 3210. The enhanced badge unitincludes all the operations previously described for the badge unit andfurther includes: a wireless receiver, e.g., an infrared receiver 5410for receiving information; a card reader 5420 for reading informationstored in the personnel card; a voice circuit 5430 for receiving voicesignals from speaker 5440 and for translating digital signals to audiosignals received from microphone 5450; a keypad 5460 for keypad entry ofdata; a display 5470 for displaying information such as data enteredfrom the keypad 5460 or data received from the receiver 5410; and amembrane switch (not shown) for special designated functions such as anemergency call or sending a selected message. A more detaileddescription of the enhanced badge unit is described in U.S. patentapplication Ser. No. 08/087,394, filed Jul. 2, 1993 which isincorporated herein by reference.

An exemplary personnel or patient card 5200 is shown in FIGS. 37 and 38and operates in a manner similar to the personnel card shown anddescribed in commonly assigned U.S. patent application Ser. No.07/924,101, filed Aug. 3, 1992 which is incorporated herein byreference. As shown, the personnel card is configured and dimensionedfor insertion within the slot 5150 of the badge unit 5110, shown in FIG.35. The front surface of the card may include a printed logo and otheridentification information.

The rear surface of the card includes an identifier circuit 5210 whichinterfaces with microcontroller 4900 of the badge unit to perform alockout function. The identifier circuit includes a ROM which has avalidation code stored therein and circuitry to read the validation codefrom the ROM and transfer the data to electrical contacts 5220. Suchcircuitry is known to those skilled in the art. Preferably, theidentifier circuit is in the form of a single integrated circuit whichis preferably dimensioned at approximately 0.25 inches square andbetween about 0.002 of an inch and about 0.004 of an inch thick formounting on the rear surface of the card. Electrical contacts 5220 ofcard 5200 are connected to identifier circuit 5210 so that when the cardis inserted into the badge unit slot 5150, contacts 5220 are engagedwith contacts 5160 of the badge unit. The identifier circuit transfers avalidation code to the microcontroller 4900 of the badge unit.Microcontroller 4900 then determines whether the card validation code isvalid so as to activate the badge unit circuitry and permit the personin possession of the card to use the badge unit. If the microcontroller4900 determines that the validation code is improper or that novalidation code is received, then microcontroller 4900 will deactivatethe badge unit circuitry and prevent the person in possession of thecard from using the badge unit.

FIG. 29 is a circuit block diagram of the patient control unit 3210.Patient control unit 3210 includes telephone keypad 4710, speaker 4720and microphone 4730 which are connected to PCM CODEC 4630 in telephonecircuit 4610 and provide telephone voice and data communications betweenthe patient stations and PBX 2430. The PCM CODEX 4630 may include a DTMFdecoder for decoding DTMF tones from the telephone keypad 4710.

FIG. 30 is a circuit block diagram of the nurse control station 2414which includes PBX interface or telephone circuitry 4610 connected tomicrocontroller 3324, keys 3328, speaker 3338, handset 3340 andmicrophone 334 2 to provide telephone communications between the nursecontrol station and the other stations and/or to provide externaltelephone communications. Staff stations 2418 include the samecomponents as shown in FIG. 25 for the patient stations 2416, except inthe staff stations, the speaker 4018, keypad 4019 and microphone 4020for providing telephone communications between the staff station and theother stations and/or to provide external telephone communications areintegrated within the staff station. Communications between the staffstations 2418 and the PBX 2430 are same as described for the patientstations 2416 and are shown in FIGS. 26 to 28.

Stations Using a PBX for Telephone and System Data Communications

Another alternative embodiment for the system configuration is shown inFIG. 31. In this embodiment private-branch exchange (PBX) 2430 isconnected to central computer 5010, to nurse control stations 2414,patient stations 2416 and staff stations 2418 and is provided tofacilitate system data communications as well as staff-to-staff,staff-to-patient and/or external telephone communications for thehospital environment.

Central computer 5010 provides standard control of PBX 2430 such asprocessing telephone data received by the PBX and providing the PBX withthe connection information to interconnect particular stations for voicecommunications. For example, if a staff member attending a nurse controlstation calls a patient station where another staff member is attendingto a patient, central processing unit 5010 processes the telephone data,e.g., patient station identity of the called party, and provides the PBXwith the necessary information to interconnect the two stations. Inaddition, central processing unit 5010 is utilized to process the systemdata to perform system functions, e.g., the call priority, nurse follow,voice paging and room monitoring functions as previously described. Thesystem data is preferably formatted in the following protocol bymicroprocessor 3512:

-   -   ST; SYSTEM DATA; SP        where the ST field is a one byte start message field. The SYSTEM        DATA field is preferably between one and 16 bytes in length and        provides the PBX with the system data, e.g, code blue data. The        SP field is a one byte stop message field.

According to an alternate embodiment, the PBX 2430 includes capabilitiesto process the telephone data and automatically connect the callingstations with the called stations for telephone and/or datacommunications independent of central processing unit 5010.

The PCM signal received at a station from PBX 2430 is then processedthrough a waveshaping and conditioning network 4650, shown in FIG. 25.Network 4650 converts the received signal from the PCM format to aserial digital format, recovers the synchronization clock to sync thetiming via phase-locked loop 4670, and recaptures the telephone voiceand data information and the system data. System Data is retrieved bythe receiver waveshaping and conditioning network 4650 using analternate mark inversion (AMI) conversion technique. The AMI conversionmethod changes the level of the output signal for each positive crossingof the zero line by the input signal, as shown in FIG. 32.

It will be understood that various modifications can be made to theembodiments of the present invention herein disclosed without departingfrom the spirit and scope thereof. For example, various systemconfigurations are contemplated, as well as various types of protocolsutilized to communicate between the numerous stations utilized withinthe system of the present invention. In addition, numerous functionsaside from those described herein may be programmed and performed in thesystem of the present invention. Therefore, the above description shouldnot be construed as limiting the invention but merely asexemplifications of preferred embodiments thereof. Those skilled in theart will envision other modifications within the scope and spirit of thepresent invention as defined by the claims appended hereto.

1. A patient control unit, including: a housing; a first switch mountedto the housing having a first terminal coupled to a first conductor anda second terminal coupled to a reference voltage; and a self-test switchmounted to the housing having a first terminal coupled to a testconductor and a second terminal coupled to the first conductor; whereinthe self-test switch actuates in response to a test signal provided onthe test conductor by a remote circuit thereby verifying continuity fromthe first switch first terminal to the remote circuit.
 2. The patientcontrol unit of claim 1, wherein the first switch is a manually operablenurse call switch, and the self-test switch is a field effecttransistor.
 3. A patient care and communication system, including: anurse station; and a plurality of remote stations coupled to the nursestation, each remote station including a processor to facilitatecommunications with the nurse station, and a patient control unitcoupled to the processor having a first switch for sending a firstsignal to the processor over a conductor, and a second switch actuatedby a second signal from the processor to verify the continuity of theconductor between the processor and the first switch.
 4. The patientcare and communication system of claim 3 wherein the first signal is anurse call signal that the remote station relays to the nurse station.5. A patient care and communication system, including: a plurality ofremote stations positioned in a plurality of patient rooms throughout afacility, each remote station including a microphone; a central stationinterconnecting the remote stations; and a plurality of nurse controlstations connected to the central station, each nurse control stationincluding a monitoring switch; wherein upon activation of a monitoringswitch at a particular nurse control station, the central station sendsa message frame to each of the plurality of remote stations to activatethe respective microphones of the plurality of remote stations, therebyenabling staff at the particular nurse control station to listen foruncharacteristic noises in the plurality of patient rooms.
 6. The systemof claim 5 wherein central station sends the message frames in apredetermined order for a predetermined period of time to permit anautomatic scan of the plurality of patient rooms.
 7. A patient care andcommunication system, including: a plurality of remote stationspositioned at various locations throughout a facility; a central stationinterconnecting the remote stations and facilitating communicationstherebetween by determining which remote stations are transmitting andwhich remote stations are receiving, and by establishing communicationlinks between the transmitting and the receiving stations; and a failsafe bus connected between each remote station; wherein upon failure ofthe central station, the remote stations operate in a local modeutilizing the fail safe bus.
 8. The system of claim 7 wherein the remotestations operate in a local mode utilizing the fail safe bus in responseto activation of a fail safe device connected to one of the remotestations.
 9. The system of claim 8 wherein the fail safe device is oneof a nurse call switch, a code blue switch, and an emergency switch. 10.A patient care and communication system, including: a plurality ofremote stations positioned at various locations throughout a facility,each remote station including a processor and a memory; a centralstation adapted to poll the remote stations to transfer a message frame;and a plurality of patient control units, each connected to a respectiveremote station, each patient control unit including a nurse call button;wherein upon activation of a nurse call button, the processor of arespective remote station generates a message frame and stores themessage frame in the memory of the respective remote station.
 11. Thesystem of claim 10 further including a plurality of zone controllersconnected between the plurality of remote stations and the centralstation, each of the zone controllers including a memory.
 12. The systemof claim 11 wherein the message frame is transferred to a zonecontroller memory when the zone controller polls the respective remotestation.
 13. The system of claim 12 wherein the message frame istransferred to the central station when the central station polls thezone controller.
 14. A patient care and communication system, including:a plurality of remote stations positioned at various locationsthroughout a facility; a plurality of zone controllers; a centralstation interconnecting the remote stations and facilitatingcommunications therebetween by determining which remote stations aretransmitting and which remote stations are receiving, and byestablishing communication links between the transmitting and thereceiving stations through the zone controllers, the communication linksbeing operated in a master-slave relationship wherein a master stationcontrols a data link included in the communication link and transmitscommand frames to a slave station, and means for allowing the remotestations to continue to operate if the central station fails.
 15. Thesystem of claim 14 wherein the zone controllers are the master stationsand the remote stations are the slave stations.
 16. The system of claim14 wherein the master station communicates with the slave station in oneof an initialization state and an information transfer state.
 17. Thesystem of claim 14 wherein the slave station responds to a command frameby sending a message frame to the master station.
 18. The system ofclaim 14 wherein the message frame includes five fields.
 19. A patientcontrol unit coupled to a remote circuit, including: a first switchhaving an ON position and an OFF position, the first switch providing afirst signal over a first conductor to the remote circuit when in the ONposition; and a second switch coupled between the first conductor and asecond conductor such that when a test signal is present on the secondconductor, the second switch provides the first signal on the firstconductor to indicate the continuity of the first conductor connectionbetween the remote circuit and the first switch.
 20. Apparatus formonitoring and controlling environmental facilities within a room of ahealth care facility, including: a wireless receiver located in theroom; a wireless transmitter located in the room having a switch fortransmitting control data to the receiver; a controller coupled to thereceiver and the environmental facilities, the controller controllingthe environmental facilities in response to the control data; and anurse control station located outside the room and coupled to thereceiver for receiving the control data to monitor the environmentalfacilities.
 21. A method for monitoring and controlling environmentalfacilities within a room of a health care facility, including:positioning a wireless receiver in the room; positioning a wirelesstransmitter in the room for transmitting control data to the receiver;connecting a controller to the wireless receiver and the environmentalfacilities, the controller being configured to receive the control datafrom the transmitter and control the environmental facilities inresponse thereto; coupling a nurse control station located outside theroom to the receiver such that the nurse control station receives thecontrol data to monitor the environmental facilities; and activating thetransmitter to transmit the control data.
 22. A patient care andcommunication system, including: a private branch exchange connected toa telephone exchange and a plurality of telephones for facilitatingtelephone communication between the telephones and the telephoneexchange; and a plurality of remote stations linked to a centralstation, each remote station having a processor for facilitatingcommunications relating to patient care with the central station,telephone circuitry connected to the private branch exchange forfacilitating telephone communication therewith, and a sensor for sensingsignals from portable transmitter units; wherein the central stationfacilitates communications among the remote stations by determiningwhich remote stations are transmitting and which remote stations arereceiving, and by establishing communication links between thetransmitting and the receiving stations, and the central station isconfigured to activate the remote stations.